NFE2L2 and breast carcinoma: Tumors from 28 breast cancer patients for whom paired data was available from before and after tamoxifen treatment were analyzed for NFE2L2, which was significantly increased after only 8–16 days of tamoxifen (p < 0.0001; Fig. 4D), showing that tumors quickly react to tamoxifen by upregulating antioxidant expression.