The current study examined the expression of TMPRSS4 and Erk1 in 436 surgical specimens of gastric cancer by immunohistochemistry, to explore the possible correlation of TMPRSS4 and Erk1 expression with clinicopathological variables, and to determine the prognostic value of TMPRSS4 and Erk1 expression. This evidence concerns the gene MAPK3 and gastric cancer.