SAG and prostate cancer: Interestingly, the accumulation of CRL substrates induced by SAG knockdown was rather selective, since other two SCF/CRL1 substrates p21 and p27 (Fig. 2e and Additional file 1: Figure S2E), two CRL5 substrates FLNA and DAB1, and one CRL3 substrate NRF2 (Additional file 1: Figure S3) were not accumulated in these two lines of prostate cancer cells upon SAG depletion.