CCND1 and hepatocellular carcinoma: According to whole-genome and exome sequencing data, CCND1 and CCNE1, encoding cyclins D1 and E1, respectively, are amplified in 4.5% of HCC patients, while CDKN2A and CDKN2B, two negative regulators of CDKs, are deleted in 10.2% and 12.5% of patients, respectively [283,333].