CDK4 and hepatocellular carcinoma: Meanwhile, knockdown of BRD3/4 did not notably alter the expression of CDK4/6, Cyclin D1, and Bcl-2 (Supplementary Figure S2C), indicating that BRD3/4 promotes proliferation of HCC cells independent of cell cycle and apoptosis escape, and that ARV-771 induced cell cycle arrest and apoptosis independent of BRD3/4.