Posted on by Dr. Francis Collins
More than 400,000 Americans have now lost their lives to COVID-19. But thousands of others who’ve gotten sick and survived COVID-19 are finding that a full recovery can be surprisingly elusive. Weeks and months after seemingly recovering from even mild cases of COVID-19, many battle a wide range of health problems.
Indeed, new results from the largest global study of this emerging “Long COVID syndrome” highlight just how real and pressing this public health concern really is. The study, reported recently as a pre-print on medRxiv, is based on survey results from more than 3,700 self-described COVID “Long Haulers” in 56 countries . They show nearly half couldn’t work full time six months after unexpectedly developing prolonged symptoms of COVID-19. A small percentage of respondents, thankfully, seemed to have bounced back from brief bouts of Long COVID, though time will tell whether they have fully recovered.
These findings are the second installment from the online Body Politic COVID-19 Support Group and its Patient-Led Research for COVID-19, which consists of citizen scientists with a wide range of expertise in the arts and sciences who are struggling with the prolonged effects of COVID-19 themselves. In an earlier survey, this group provided a first-draft description of Long COVID syndrome, based on the self-reported experiences of 640 respondents.
In the new survey-based study led by Athena Akrami, with Patient-Led Research for COVID-19 and University College London, England, the goal was to characterize the experiences of many more people with Long COVID syndrome. They now define the syndrome as a collection of symptoms lasting for more than 28 days.
This second survey emphasizes the course and severity of more than 200 symptoms over time, including those affecting the heart, lungs, gastrointestinal system, muscles, and joints. It took a particularly in-depth look at neurological and neuropsychiatric symptoms, along with the ability of COVID-19 survivors to return to work and participate in other aspects of everyday life.
The 3,762 individuals who responded to the survey were predominately white females, between the ages of 30 and 60, who lived in the United States. As in the previous survey, the study included adults with symptoms consistent with COVID-19, whether or not the infection had been confirmed by a viral or antibody test. That is a potential weakness of the study, as some of these individuals may have had some other inciting illness. But many of the study’s participants developed symptoms early on in the pandemic, when testing was much more limited than it is now.
More than half never sought hospital care. Only 8 percent said that they’d been admitted to the hospital for COVID-19. And yet, 2,464 respondents reported COVID-19 symptoms lasting six months or longer. Most of the remaining respondents also continued to have symptoms, although they had not yet reached the six-month mark.
Among the most common symptoms were fatigue, worsening of symptoms after physical or mental activity, shortness of breath, trouble sleeping, and “brain fog,” or difficulty thinking clearly. The majority—88 percent—said they coped with some form of cognitive dysfunction or memory loss that to varying degrees affected their everyday lives. That includes the ability to make decisions, have conversations, follow instructions, and drive.
Those who had prolonged symptoms of COVID-19 for more than six months reported contending with about 14 symptoms on average. Most also reported that they’d had a relapse of symptoms, seemingly triggered by exercise, mental activity, or just everyday stress. When surveyed, nearly half of respondents said they’d had to reduce their hours at work due to the severity of their symptoms. Another 22 percent weren’t working at all due to their Long COVID.
The findings show that—even in those people who don’t require hospitalization for severe COVID-19—the condition’s prolonged symptoms are having a major impact on lives and livelihoods, both here and around the world. While the number of people affected isn’t yet known, if even a small proportion of the vast numbers of people infected with COVID-19 develop Long COVID syndrome, it represents a significant public health concern.
Another recent study from China further documents the tendency of COVID-19-related symptoms to linger past the usual recovery time for a respiratory virus . The study, published in Lancet, showed that six months after the onset of illness, more than 75 percent of people hospitalized with COVID-19 in Wuhan between January and May 2020 continued to report at least one symptom. Fatigue, muscle weakness, sleep difficulties, anxiety, and depression all were common. More than half of individuals also had significant persistent lung abnormalities, which were more common in those who’d been more severely ill.
It’s essential for us to learn all we can about how SARS-CoV-2, which is the coronavirus that causes COVID-19, leads to such widespread symptoms. It’s also essential that we develop ways to better treat or prevent these symptoms. The NIH held a workshop last month to summarize what is known and fill in key gaps in our knowledge about Long COVID syndrome, which is clinically known as post-acute sequelae of COVID-19 (PASC). In December, Congress authorized funding for continued research on PASC, including an appropriation of funds for NIH to support continued study of these prolonged health consequences.
As these efforts and others proceed in the coming months, the hope is that we’ll gain much more insight and get some answers soon. And, if you’ve had or are currently experiencing symptoms of COVID-19, there’s still time to share your data by participating in the Patient-Led Research for COVID-19’s second survey.
 Characterizing Long COVID in an international cohort: 7 months of symptoms and their impact. David HE et al. Medrxiv. 27 December 27 2020.
 6-month consequences of COVID-19 in patients discharged from hospital: a cohort study. Huang C, Huang L, et al. Lancet. 2021 Jan 16;397(10270):220-232.
COVID-19 Research (NIH)
Posted on by Dr. Francis Collins
Sheltering at home for more than two months has made many of us acutely aware of just how much we miss getting out and interacting with other human beings. For some, the coronavirus disease 2019 (COVID-19) pandemic has also triggered a more selfless need: to be a good neighbor to the most vulnerable among us and help them stay well, both mentally and physically, during this trying time.
The term “good neighbor” definitely applies to Pablo Vidal-Ribas Belil, a postdoctoral fellow at NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). Though Vidal-Ribas has his hands full caring for his 4-year-old son in their condo, which is located near NIH’s main campus in Bethesda, MD, he wasn’t too busy to notice that some of his neighbors were in need of help.
Vidal-Ribas extended a helping hand to pick up groceries and prescriptions for the older woman downstairs, as well as several more of his elderly neighbors. He and other concerned neighbors also began enlisting more volunteers to join a neighborhood coronavirus task force. There are now up to 30 volunteers and sometimes hold virtual meetings.
To try to reach everyone in the more than 950-unit Parkside Condominium community, the group coordinated its activities with the help of the management office. They also issued flyers and email messages via the neighborhood list serv, offering to assist people at greatest risk for COVID-19, including seniors and those with compromised immune systems or other serious conditions, by shopping for essential items and dropping the items off at their doors.
The personal interest and care of Vidal-Ribas also comes with medical expertise: he’s a clinical psychologist by training. Vidal-Ribas, who is originally from Barcelona, Spain, came to the United States four years ago to work with an NIH lab that specializes in the study of depression and related conditions in young people. Last year, Vidal-Ribas moved to NICHD as a Social and Behavioral Sciences Branch Fellow, where he now works with Stephen Gilman. There, he explores prenatal and early developmental factors that contribute to attempts at suicide later in life.
His expertise as a psychologist has come in handy. Vidal-Ribas has found that many of the individuals requesting help with grocery items or prescriptions also want to talk. So, the team’s efforts go a long way toward providing not only basic necessities, but also much-needed social and emotional support.
In recognition of this need, the group has expanded to offer virtual chats and other community activities, such as physically distanced games, conversations, or story times. One talented young volunteer has even offered to give music concerts remotely by request. Folks know they can call on Vidal-Ribas and some of the most active task force volunteers at any time.
Vidal-Ribas reports that they’ve taken great care to follow the latest guidelines from the Centers for Disease Control and Prevention on how to protect yourself and others from COVID-19 to ensure that those volunteering their time do so safely. He and other volunteers typically buy for multiple neighbors at once while they do their own personal shopping to reduce the number of outings. They then leave the bags with groceries or prescriptions at their neighbors’ doors with no direct contact. As far as he knows, none of his vulnerable neighbors have come down with COVID-19.
Vidal-Ribas says he’s prepared to continue his volunteer outreach for as long as it takes. And, even when the threat of COVID-19 subsides, he’ll keep on lending a hand to his neighbors. It’s one of the ways he stays connected to his community and grounded within himself during this difficult time. By sharing his story, he hopes it will inspire others to do what they can to help others in need to stay safe and well.
Coronavirus (COVID-19) (NIH)
Social and Behavioral Sciences Branch Fellows (National Institute of Child Health and Human Development/NIH)
Stephen Gilman ((National Institute of Child Health and Human Development/NIH)
Posted on by Dr. Francis Collins
The coronavirus 2019 (COVD-19) pandemic has brought into sharp focus many of the troubling things that we already knew about health disparities in the United States but have failed to address. With the bright light now shining on this important issue, it is time to talk about the role research can play in reducing the disproportionate burden of COVID-19, as well as improving the health of all people in our great nation.
In recent weeks, we’ve seen a growing list of disturbing statistics about how blacks, Hispanics, tribal communities, and some other racial, ethnic, and disadvantaged socioeconomic groups are bearing the brunt of COVID-19. One of the latest studies comes from a research team that analyzed county-by-county data gathered about a month ago. Their findings? The 22 percent of U.S. counties that are disproportionately black accounted for 52 percent of our nation’s COVID-19 cases and 58 percent of COVID-19 deaths. In a paper awaiting peer review, the team, led by Emory University, Atlanta, and amfAR, the Foundation for AIDS Research, Washington, DC., noted that neither the size of the county nor whether it was urban or rural mattered .
Recently, I had an opportunity to discuss the disparate burden of COVID-19 with Dr. Eliseo Pérez-Stable, Director of NIH’s National Institute on Minority Health and Health Disparities (NIMHD). Besides leading an institute, Dr. Pérez-Stable is a widely recognized researcher who studies various factors that contribute to health disparities. Our conversation took place via videoconferencing, with him linking in from his home in Washington, D.C., and me from my home in nearby Maryland. Here’s a condensed transcript of our chat:
Collins: Eliseo, you and I recently had a chance to have a pretty intense discussion with the Congressional Black Caucus about health disparities and the COVID-19 pandemic. So, could you start off with a little bit about what populations are being hit hardest?
Pérez-Stable: Collecting data about disease incidence and mortality on the basis of race and ethnicity and other important demographic factors, like socioeconomic status, had really been absent in this pandemic until recently.
Part of that I think is entirely understandable. Hospitals were pressed with a surge of very sick patients, and there was a certain amount of fear and panic in the community. So, people were not completing all these forms that usually get turned in to the health departments and then forwarded to the CDC. If you go back in history, similar things happened in the early 1980s with the HIV epidemic. We weren’t collecting data on race and other sociodemographic variables initially. But, with time, we did complete these data and a picture emerged.
With the COVID-19 pandemic, obviously, the outcomes are much faster, with over 60,000 deaths in just a matter of three months. And we started to see reports, initially out of Connecticut, Milwaukee, Chicago, and New Orleans, that African Americans were dying at a disproportionate rate.
Now, the initial—and I think still the most likely—explanation for this higher mortality relates to two factors. The first is a higher rate of co-morbidities. We know that if you have cardiovascular disease, more than mild obesity, or diabetes, you’re more likely to get severe COVID-19 and potentially die from it. So, we could have just said, “Aha! It’s obvious why this population, and others with higher rates of co-morbidities might be expected to have higher rates of severe disease and higher mortality.”
But there is a second factor that relates to getting infected, for which we have much-less clear data. There was recently a map in The Washington Post showing the distribution of the rate of COVID-19 infections in Washington, D.C., by ward. The highest rates are in the wards that are east of the Anacostia River, which are about 90 percent African American. So, there is an appearance of a correlation between the proportion of African Americans in the community and the rate of Covid-19 infection. Now why could that be?
Collins: Yes, what explains that?
Pérez-Stable: Well, I think crowding is part of it, certainly in this neighborhood. A second option would be multiple families living under one roof.
Collins: So, you can’t exactly practice physical distancing very well in that situation.
Pérez-Stable: Absolutely. You and I can go into our respective rooms, probably have our respective bathrooms, and socially and physically isolate from the rest of the household if need be. Many people can’t do that. They have three generations in one small apartment, all using one bathroom, maybe two bedrooms for six or eight people.
So, we do face different conditions by which one casual infection can lead to much more community transmission. But much information still needs to be ascertained and there does seem to be some regional variance. For example, in Chicago, Milwaukee, and Atlanta, the reports, at least initially, are worse than they are in Connecticut or Florida. Also, New York City, which has been the epicenter of the U.S. for this pandemic, has an increased rate of infections and mortality among Latino-Hispanic populations as well. So, it isn’t isolated to an African-American issue.
Collins: What about access to healthcare?
Pérez-Stable: Again, we can postulate based on a little bit of anecdote and a little bit of data. I’m a general internist by background, and I can see the enormous impact this pandemic has had on healthcare settings.
First, elective ambulatory visits and elective admissions to the hospital have been postponed, delayed, or cancelled. About 90 percent of ambulatory care is occurring through telemedicine or telephone connections, so in-person visits are occurring only for really urgent matters or suspected COVID-19.
If you have health insurance and can use systems, you can probably, through telephone triage with a nurse, get either approval or nonapproval for being tested [for COVID-19], drive to a place, get tested by someone wearing protective equipment, and never actually have to visit with anyone. And you’ll get your result now back as soon as one day, depending on the system. Now, if you’re insured, but don’t really know how to use systems, navigating all these things can be a huge challenge. So, that could be a factor.
People are also afraid to come to clinic, they’re afraid to show up at the emergency room, because they’re afraid to get infected. So, they’re worried about going in, unless they get very sick. And when they get very sick, they may be coming in with more advanced cases [of COVID-19].
So, telephone triage, advice from clinicians on the phone, is critical. We are seeing some doctors base their decisions on whether a person is able to breathe okay on the phone, able to say a whole sentence without catching their breath. These kinds of basic things that we learned in clinical medicine training are coming into play in a big way now, because we just cannot provide the kind of care, even in the best of circumstances, that people may need.
Of course, uninsured patients will have even more barriers, although everyone in the healthcare system is trying their best to help patients when they need to be helped, rather than depend on insurance triage.
Collins: A big part of trying to keep the disease from spreading has been access to testing so that people, even those with mild symptoms, can find out if they have this virus and, if so, quarantine and enable public health workers to check out their contacts. I’m guessing, from what you said, that testing has been happening a lot less in urban communities that are heavily populated by African Americans and that further propagates the spread of the disease. Am I right?
Pérez-Stable: So far, most testing has been conducted on the basis of symptoms. So, if you have enough symptoms that you may potentially need to be hospitalized, then you get tested. Also, if you’re a healthcare worker who had contact with a COVID-19 patient, you might be tested, or if there’s someone you’ve been very close to that was infected, you may be tested. So, I don’t think so much it’s a matter of disproportionate access to testing by one group or another, as much as that the overall triage and selection criteria for testing have been rather narrow. Up until now, it has not been a simple process to get tested for COVID-19. As we scale up and get better point-of-care tests and much easier access to getting tested, I think you’ll see dissemination across the board.
Collins: It’s interesting we’re talking about this, because this is an area that Congress recently came to NIH and said, “We want you to do something about the testing by encouraging more technology, particularly technology that can be distributed to the point-of-care, and that is out in the community.”
Everyone wants a test that gives you a quick turnaround, an answer within an hour, instead of maybe a day or two. A big part of what NIH is trying to do is to make sure that if we’re going to develop these new testing technologies, they get deployed in places that otherwise might not have much access to testing—maybe by working through the community health centers. So, we’re hoping we might be able to make a contribution there.
Pérez-Stable: The economic factors in this pandemic are also huge. A significant proportion of the population that we’re referring to—the disparity population, the minorities, the poor people—work in service jobs where they’re on the front line. They were the restaurant servers and people in the kitchen, they’re still the bus drivers and the Uber drivers, and those who are working in pharmacies and supermarkets.
On the one hand, they are at higher risk for getting infected because they’re in more contact with people. On the other hand, they’re really dependent on this income to maintain their household. So, if they test positive or get exposed to COVID-19, we really do have a challenge when we ask them to quarantine and not go to work. They’re not in a position where they have sick leave, and they may be putting themselves at risk for being laid off.
Collins: Eliseo, you’ve been studying health disparities pretty much your whole research career. You come from a community where health disparities are a reality, having been born in Cuba and being part of the Latino community. Did you expect that COVID-19 would be this dramatic in the ways in which it has so disproportionately affected certain groups?
Pérez-Stable: I can’t say that I did. My first thought as a physician was to ask: “Is there any reason to think that an infectious agent like COVID-19 would disproportionally infect or impact any population?” My gut answer was “No.” Infectious diseases usually seem to affect all people; sort of equal opportunity invaders. There are some data that would say that influenza and pneumonia are not any worse among African Americans or Latinos than among whites. There are some slight differences in some regions, but not much.
Yet I know this a question that NIH-funded scientists are interested in addressing. We need to make sure that there aren’t any particular susceptibility factors, possibly related to genetics or the lung epithelium, that lead to such different COVID-19 outcomes in different individuals. Clearly, something must be going on, but we don’t know what that is. Maybe one of those factors tracks through race or ethnicity because of what those social constructs represent.
I recently listened to a presentation by Rob Califf, former FDA Commissioner, who spoke about how the pandemic has created a spotlight on our disparities-creating system. I think much of the time this disparities-creating system is in the background; it doesn’t really affect most people’s daily lives. Now, we’re suddenly hit with a bucket of cold water called COVID-19, and we’re saying what is going on and what can we do about it to make a difference. I hope that, once we begin to emerge from this acute crisis, we take the opportunity to address these fundamental issues in our society.
Collins: Indeed. Let’s talk about what you’re doing at NIMHD to support research to try to dig into both the causes of health disparities and the interventions that might help.
Pérez-Stable: Prompted by your motivation, we started talking about how minority health and health disparities research could respond to this pandemic. In the short-term, we thought along the lines of how can we communicate mitigation interventions, such as physical distancing, in a more effective way to our communities? We also asked what we could do to enhance access to healthcare for our populations, both to manage chronic conditions and for diagnosis and treatment of acute COVID-19.
We also considered in the mid- and long-term effects of economic disruption—this surge of unemployment, loss of jobs, loss of insurance, loss of income—on people’s health. Worries include excess use of alcohol and other substances, and worsening of mental and emotional well-being, particularly due to severe depression and chronic mental disorders not being well controlled. Intimate partner violence has already been noted to increase in some countries, including France, Spain, and the United States, that have gone on physical distancing interventions. Similarly, child abuse can be exacerbated under these circumstances. Just think of 24/7 togetherness as a test of how people can hold it together all the time. I think that that can bring out some fragility. So, interventions to address these, that really activate our community networks and community-based organizations, are real strengths. They build on the resilience of the community to highlight how we can get through this difficult period of time.
I feel optimistic that science will bring answers, in the form of both therapies and vaccines. But in the meantime, we have a way to go and we a lot to do.
Collins: You mentioned the promise of vaccines. The NIH is working intensively on this, particularly through a partnership called ACTIV, Accelerating Covid-19 Therapeutic Interventions and Vaccines. We hope that in several more months, we’ll be in a position to begin testing these vaccines on a large scale, after having some assurances about their safety and efficacy. From our conversation, it sounds like we should be trying to get early access to those vaccines to people at highest risk, including those in communities with the heaviest burden. But how will that be received? There hasn’t always been an easy relationship between researchers, particularly government researchers, and the African-American community.
Pérez-Stable: I think we have learned from our historical experiences that mistrust of the system is real. To try to pretend that it isn’t there is a big mistake. Address these concerns upfront, obtain support from thought leaders in the community, and really work hard to be inclusive. In addition to vaccines, we need participation in any clinical trials that are coming up for therapeutics.
We also need research on how optimally to communicate this with all the different segments of the population. This includes not just explaining what it means to be eligible for vaccine trials or therapeutic trials, but also discussing the consequences of, say, getting tested, whether it be a viral or antibody test. What does the information mean for them?
Most people just want to know “Am I clear of the virus or not?” That certainly could be part of the answer, but many may require more nuanced responses. Then there’s behavior. If I’m infected and I recover, am I safe to go back out and do things that other people shouldn’t do? We’d love to be able to inform the population about that. But, as you know, we don’t really have the answers to that just yet.
Collins: Good points. How do we make sure, when we’re trying to reach out to populations that have shouldered such a heavy burden, that we’re actually providing information in a fashion that is readily understood?
Pérez-Stable: One thing to keep in mind is the issue of language. About 5 to 10 percent of U.S. adults don’t speak English well. So, we really have to address the language barrier. I also want to highlight the challenge that some tribal nations are facing. Navajo country has had particular challenges with COVID-19 infections in a setting of minimal medical infrastructure. In fact, there are communities that have to go and get their water for the day at a distant site, so they don’t have modern plumbing. How can we recommend frequent hand washing to someone who doesn’t even have running water at home? These are just a few examples of the diversity of our country that need to be addressed as we deal with this pandemic.
Collins: Eliseo, you’ve given us a lot to think about in an obviously very serious situation. Anything you’d like to add?
Pérez-Stable: In analyzing health outcomes, researchers often think about responses related to a metabolic pathway or to a gene or to a response to a particular drug. But as we use the power of science to understand and contain the COVID-19 pandemic, I’d like to re-emphasize the importance of considering race, ethnicity, socioeconomic status, the built environment, the social environment, and systems. Much of the time these factors may only play secondary roles, but, as in all science related to humans, I think they have to be considered. This experience should be a lesson for us to learn more about that.
Collins: Thank you for those wonderful, inspiring words. It was good to have this conversation, Eliseo, because we are the National Institutes of Health, but that has to be health for everybody. With COVID-19, we have an example where that has not turned out to be the case. We need to do everything we can going forward to identify ways to change that.
 Assessing Differential Impacts of COVID-19 on Black Communities. Millet GA et al. MedRxiv. Preprint posted on May 8, 2020.
Coronavirus (COVID-19) (NIH)
Director’s Corner (National Institute on Minority Health and Disparities/NIH)
COVID-19 and Racial/Ethnic Disparities. Webb Hooper M, Nápoles AM, Pérez-Stable EJ.JAMA. 2020 May 11.
amfAR Study Shows Disproportionate Impact of COVID-19 on Black Americans, amfAR News Release, May 5, 2020.
Posted on by Dr. Francis Collins
These colorful lights might look like a video vignette from one of the spectacular evening light shows taking place this holiday season. But they actually aren’t. These lights are illuminating the way to a much fuller understanding of the mammalian brain.
The video features a new research method called BARseq (Barcoded Anatomy Resolved by Sequencing). Created by a team of NIH-funded researchers led by Anthony Zador, Cold Spring Harbor Laboratory, NY, BARseq enables scientists to map in a matter of weeks the location of thousands of neurons in the mouse brain with greater precision than has ever been possible before.
How does it work? With BARseq, researchers generate uniquely identifying RNA barcodes and then tag one to each individual neuron within brain tissue. As reported recently in the journal Cell, those barcodes allow them to keep track of the location of an individual cell amid millions of neurons . This also enables researchers to map the tangled paths of individual neurons from one region of the mouse brain to the next.
The video shows how the researchers read the barcodes. Each twinkling light is a barcoded neuron within a thin slice of mouse brain tissue. The changing colors from frame to frame correspond to one of the four letters, or chemical bases, in RNA (A=purple, G=blue, U=yellow, and C=white). A neuron that flashes blue, purple, yellow, white is tagged with a barcode that reads GAUC, while yellow, white, white, white is UCCC.
By sequencing and reading the barcodes to distinguish among seemingly identical cells, the researchers mapped the connections of more than 3,500 neurons in a mouse’s auditory cortex, a part of the brain involved in hearing. In fact, they report they’re now able to map tens of thousands of individual neurons in a mouse in a matter of weeks.
What makes BARseq even better than the team’s previous mapping approach, called MAPseq, is its ability to read the barcodes at their original location in the brain tissue . As a result, they can produce maps with much finer resolution. It’s also possible to maintain other important information about each mapped neuron’s identity and function, including the expression of its genes.
Zador reports that they’re continuing to use BARseq to produce maps of other essential areas of the mouse brain with more detail than had previously been possible. Ultimately, these maps will provide a firm foundation for better understanding of human thought, consciousness, and decision-making, along with how such mental processes get altered in conditions such as autism spectrum disorder, schizophrenia, and depression.
Here’s wishing everyone a safe and happy holiday season. It’s been a fantastic year in science, and I look forward to bringing you more cool NIH-supported research in 2020!
 High-Throughput Mapping of Long-Range Neuronal Projection Using In Situ Sequencing. Chen X, Sun YC, Zhan H, Kebschull JM, Fischer S, Matho K, Huang ZJ, Gillis J, Zador AM. Cell. 2019 Oct 17;179(3):772-786.e19.
 High-Throughput Mapping of Single-Neuron Projections by Sequencing of Barcoded RNA. Kebschull JM, Garcia da Silva P, Reid AP, Peikon ID, Albeanu DF, Zador AM. Neuron. 2016 Sep 7;91(5):975-987.
Zador Lab (Cold Spring Harbor Laboratory, Cold Spring Harbor, NY)
NIH Support: National Institute of Neurological Disorders and Stroke; National Institute on Drug Abuse; National Cancer Institute