TSC2 and breast cancer: Since SGK1 was verified to have a role in BC cells’ resistance to AKT inhibitors under PDK1 regulation [82], the PDK1–SGK1 axis was further revealed to prevail against AKT inhibition by activating mTORC1 via directly phosphorylating TSC2 in BC cells resistant to PI3 Kα inhibitors, while PDK1 deletion re-sensitized BC cells to PI3 Kα inhibitors [83].