CDK4 and hepatocellular carcinoma: In cirrhotic HCC, the ER group with hypermethylation exhibits the top 10 prominent pathways, which encompass the activation of HOX genes, defective p16INK4A binding to CDK4 and CDK6, FOXO-mediated transcription of cell death genes, TP53 regulated transcription, G protein-gated potassium channels, extracellular matrix organization, adherent junction interactions, and the aberrant regulation of the mitotic cell cycle due to RB1 defects.