Next, we assessed the frequency of CDKN2A methylation in tumor and non-tumor tissue samples of 34 patients with liver metastases (Table 3) and 11 patients with adenocarcinomas of the biliary tract and gall bladder (CCC-group) as well as from 7 patients with benign liver tumors (Table 2). This evidence concerns the gene CDKN2A and carcinoma.