SAG and Familial prostate cancer: To gain mechanistic insight into SAG action, we used the loss-of-function approach in two human prostate cancer cell lines and found that SiRNA-based SAG knockdown caused in general accumulation of PHLPP1 and DEPTOR with consequential inactivation of pAKT and mTORC1 activity (Figs. 2e and Additional file 1: Figure S2E).