MAPK3 and cancer: For GC patients, while a significant increase of the expression tissue level of ERK1/2 was always observed in the tissues at T2, T3, and T4 stages, no modification of the p-ERK1/2 expression level was noted when progressing from cancer stages T1 to T3, thus this was significantly higher only at stage T4 as compared to stage T1 (Figures 5C, D).