Richard Flavell’s research focuses on the molecular and cellular basis of the immune response, using transgenic and gene-targeted mice to study innate and adaptive immunity, T-cell tolerance and activation in immunity and autoimmunity, apoptosis, and the regulation of T-cell differentiation. Richard is a co-discoverer of introns in cellular genes: he showed that DNA methylation correlates inversely with, and prevents, gene expression.

He was the first to develop reverse genetics as a postdoctoral researcher; he is a pioneer in the use of this approach in vivo to study function. His laboratory has shown that the NLRP6 inflammasome maintains homeostasis with the gut microbiota through controlling the mucus layer. In the absence of this control, dysbiosis and hence susceptibility to IBD, metabolic syndrome and colon cancer results.

Richard showed that dysbiotic microbes drive intestinal inflammation and elicit specific IgA responses that identified the organisms that appear to play a causal role in Crohn’s disease and ulcerative colitis in humans. He is a member of the US National Academy of Sciences and the US National Academy of Medicine.