CDKN2A and cancer: Genomic analyses of Barrett’s esophagus progression identified 9p21.3 CNVs (encompassing FHIT exon 5 and CDKN2A/B loci) as cardinal genomic events in 88% of esophageal adenocarcinoma cases,162 while 9p13 amplifications that activate oncogenes, such as VCP, DCTN3, and STOML2, drive phenotypic diversification in oral precancer-to-cancer transitions.163