The PDK1-SGK1 axis has been characterized as a drug-resistant mechanism of the PI3Kα inhibitor alpelisib in breast cancer, in which mTORC1 is activated via direct phosphorylation and inhibition of TSC2, a negative mTORC1 regulator, by SGK1 (Castel et al., 2016). This evidence concerns the gene TSC2 and breast cancer.