MAPK3 and neoplasm: Furthermore, the immunohistochemistry staining showed that the expression of phosphorylated p38MAPK and ERK1/2 were significantly increased in tumor tissues of Adamts18 KO mice when compared with WT littermates [pERK positive area: WT vs. KO, 641 ± 10 vs. 674 ± 17, P = 0.002; p38MAPK positive area: WT vs. KO, 628 ± 13 vs. 660 ± 9, P = 0.0008) (Figure 6C).