MAP2K1 and breast carcinoma: From these data, it is tempting to speculate that breast cancer patients undergoing antiestrogen therapy may benefit from a diet low in vitamin E. Minimally, further studies are needed the better to define the mechanism of action of vitamin E, its effect on the MEK1/MAPK prosurvival axis that contributes to the regulation of the Bim proapototic action, and its effect on the efficacy of endocrine therapy for breast cancer.