FGFR2 and Crohn disease: Relevant to this, FGFR2 may play a causal role in the natural history of CRCs arising from inflammatory bowel disease (IBD): the p38 pathway downstream of FGFR2b drives the chronic inflammatory phenotypes of ulcerative colitis and Crohn's disease [174, 175], with colitis-associated tumors characterised by gain-of-function FGFR2 aberrations [172, 176] such as have been reported in fewer than 2% of sporadic CRC [177].