MAPK1 and irritable bowel syndrome: Although many of the RR-specific gene expression changes differed significantly between IBS and IBD patients and significantly more gene expression changes were observed in IBD than in IBS, changes in upstream and downstream targets of NF-κB (e.g. MAPK, P38 MAPK, MAPK8) after the RR-MBI were common to both IBS and IBD, supporting the notion that RR elicitation may counteract the effects of stress on IBS and IBD through common changes in stress-related gene expression.