KDM4C and pachyonychia congenita: Other potentially functional SNPs relevant to PC and prioritized in the 2D approach comprised 6 SNPs (LMI ≤ 5.60) in the vicinities of CDKN2A/p16, a gene that is almost universally inactivated in PC [54] and that is mutated in some hereditary forms of PC [55, 56], with three variants (LMI ≤ 5.48) in CDKN2A-AS1 and two (LMI ≤ 5.88) in CDKN2B/p15, other important cell-cycle regulators; three variants in KDM4C (LMI ≤ 11.27), a Lys demethylase 4C highly expressed in PC [57]; and two SNPs tagging ROR2 (LMI ≤ 5.57), a member of the Wnt pathway that plays a relevant role in PC [58].