MAPK3 and gastric cancer: Immunoblot (Fig. 5a, upper panel) as well as its densitometry analysis (Fig. 5a, lower panel) showed the significant increase of ph-MSK1 (p < 0.001), p38 (p < 0.01), and ph-p38 (p < 0.001), while ph-ERK1/2 (p < 0.001) levels significantly decrease in tumor compared to resection margin tissues, thus, indicating p38-mediated activation of MSK1 in GC.