In 2019, a study conducted by Silva-Figueroa et al. [17] introduced a nomogram based on immunohistochemical (IHC) staining of parafibromin, Rb, Ki-67, E-cadherin, PGP9.5, and galectin-3 to assist in the diagnosis of PC. The gene discussed is UCHL1; the disease is pachyonychia congenita.