MTOR and breast cancer: The overexpression of ABCG2 and ABCB1 was shown to suppress the intracellular uptake of LY3023414 leading to resistance in cancer cells.147 To understand the mechanism of mTOR inhibitors resistance in human cancers, a resistance screen was performed in MCF-7 breast cancer cells and discovered somatic mutations A2034V and F2108L in the FRB-FKBP12 domain of the mTOR to acquire resistance against rapamycin.