CDKN2A and cancer: We found a 5.1 kb CDR (chr9: 21,970,277 - 21,975,386, hg19) that spanned from the P16INK4A promoter to intron-2 in 83 (90%) of 92 reported cancer cell lines or tissue samples containing interstitial CDKN2A deletions (Figure 1B, blue lines).