SPOP and prostate cancer: While, several samples bearing SPOP mutant still displayed a relatively weak expression of PDK1, possibly due to non-loss-of-function mutations occurred in SPOP. Functionally, since prostate cancer cells expressing SPOP mutants displayed enhanced colony-formation ability in monolayer culture compared with that of cells expressing intact SPOP (Fig. S3D), we observed that SPOP mutants-induced colony formation could be largely restricted by depleting PDK1 (Fig. 2K-L, S3E-F).