MAPK3 and colitis: After induction of colitis, there was weight loss, diarrhea, intestinal bleeding, colon shrinkage, ulceration, erosion, edema, and inflammation marked by cellular infiltration, an elevation of MPO, phosphorylation of IKKα and IκB, ERK1/2 and SAPK/JNK, increased NF-kB and MAPK activity, and increased levels of p38 expression.