CDKN2A and hepatocellular carcinoma: Comparing p16 methylation and hypermethylation in the HCC tissues according to tumor grade, methylation or hypermethylation was detected in 16 of 24 (61%) well differentiated HCCs, 11 of 14 (78%) moderately differentiated HCCs, and 4 of 5 (80%) poorly differentiated HCCs.