As is the case for clinical samples of breast cancer, in a panel of breast cell lines, we observed that aggressive and metastatic ER- breast cancer cells exhibit higher pEZH2(T367), EZH2, and p-p38 proteins compared to benign and less aggressive ER-positive breast cancer cells and nontumorigenic breast cells (Supplementary Fig. 1G). Here, MAPK14 is linked to breast cancer.