CDKN2A and lichen sclerosus et atrophicus: Most studies interrogate the CpG status of CDKN2A locus which codes the tumor suppressors p16INK4A and p14ARF. Co-inactivating mutations in CDKN2A and p53 were observed more frequently in lichen sclerosus-derived tumors than in HPV-derived cases (p = 0.053) in one study [66].