CDK4 and benign prostatic hyperplasia: Meanwhile, Western blot manifested that apoptosis-related proteins (BAX, cleaved-caspase 9 and cleaved-caspase 3) were down-regulated, and anti-apoptosis protein Bcl-2 and cycle-associated proteins (Cyclin D1, CDK4 and CDK6) were up-regulated in T-BPH rats, all of which were reversed by TRO intervention (Fig. 10J and Additional file 11: Fig. S7B).