CDK4 and hepatocellular carcinoma: Notably, pharmacological inhibition of CDK4/6 using Abemaciclib or genetic depletion of CDK4 and CDK6 in HCC cells significantly decreases the protein levels of YAP1 and its downstream targets, such as CYR61 and CTGF, without affecting YAP1 mRNA levels (Figs. 1C–F and S3).