The observation that the functional interplay between Dot1L and menin has an active part in the mitogenic and cell survival effects of estrogen-sensitive and AE-resistant BC cells, raises the possibility that targeting both proteins at once with specific inhibitors could represent a new strategy against BCs and overcoming high dose side effects and modest efficacy in patients exposed to single doses of Dot1L inhibitors [47]. This evidence concerns the gene MEN1 and breast cancer.