In 4 prostate cancer cell lines, which collectively model castration-sensitive disease (LNCaP), AR-positive CRPC (V16D), AR-positive enzalutamide-resistant CRPC (MR49F) and AR-negative CRPC (PC3), we observed a significant additive anti-proliferative effect when combing CDKI-73 and AZD5153 (Fig. 6a). Here, AR is linked to prostate cancer.