Back in the early 1930s, Burrill Crohn, a gastroenterologist in New York, decided to examine intestinal tissue biopsies from some of his patients who were suffering from severe bowel problems. It turns out that 14 showed signs of severe inflammation and structural damage in the lower part of the small intestine. As Crohn later wrote a medical colleague, “I have discovered, I believe, a new intestinal disease …” 
More than eight decades later, the precise cause of this disorder, which is now called Crohn’s disease, remains a mystery. Researchers have uncovered numerous genes, microbes, immunologic abnormalities, and other factors that likely contribute to the condition, estimated to affect hundreds of thousands of Americans and many more worldwide . But none of these discoveries alone appears sufficient to trigger the uncontrolled inflammation and pathology of Crohn’s disease.
Other critical pieces of the Crohn’s puzzle remain to be found, and Gwendalyn Randolph thinks she might have her eyes on one of them. Randolph, an immunologist at Washington University, St. Louis, suspects that Crohn’s disease and other related conditions, collectively called inflammatory bowel disease (IBD), stems from changes in vessels that carry nutrients, immune cells, and possibly microbial components away from the intestinal wall. To pursue this promising lead, Rudolph has received a 2015 NIH Director’s Pioneer Award.