CDKN2A and cancer: For example, paired esophageal SCCs and intraepithelial neoplasia exhibit overlapping CNVs in genomic regions governing DNA repair, apoptosis, proliferation, and cell adhesion, notably at 11q13.3 (CCND1), 3q26.33 (SOX2), 2q31.2 (NFE2L2), and 9p21.3 (CDKN2A).160 Hepatocarcinogenesis models reveal an initial loss of DNA copy numbers of tumor suppressor genes in the 4q and 13q regions,161 thereby conferring survival benefits to cancer cells.