MAP2K1 and breast carcinoma: ERK1/2 was activated by a pathophysiologically relevant concentration (65 mM) of alcohol in the human breast cancer cell line MCF-7, and activated ERK1/2-induced increases in cell proliferation up to 400%, but when an MEK1 inhibitor (PD98059) was administered with alcohol, the cell proliferation was reduced to 200% (7).