PDK1 and breast carcinoma: A similar tumor growth bypass pathway was also found in breast cancer; Castel et al. (54) showed that PDK1-SGK1 signaling sustained AKT-independent mTORC1 activation and confers resistance to PI3Kα inhibition, indicating that either PDK1 or SGK1 blockade prevents mTORC1 activation and restores the antitumoral effects of PI3Kα inhibition in resistant cells.