RB1 and urinary bladder cancer: In regard to the Rb-independent effects, has been also reported that the CDK4/6 inhibitor Palbociclib induces a significant cell cycle arrest in Rb-silenced HepG2 and Hu7 hepatocellular carcinoma cell lines [47], as well as induces apoptosis of T-acute lymphoblastic leukaemia [48] and bladder cancer cells [49].