APEX1 and melanoma: As far as the pigmentation-related genetic factors are concerned, besides MITF mutations, the alterations of MITF-regulated MC1R (melanocortin-1 receptor), SLC45A2 (solute carrier family 45 member 2) and OCA2 (oculocutaneous albinism type 2) genes, as well as those of the melanosomal TYR (tyrosinase) and TYRP1 (tyrosinase-related protein 1) and DNA repair gene defects of TERT (telomerase reverse transcriptase) and APEX1 (apurinic/apyrimidinic endodeoxyribonuclease 1), are also significant contributors, increasing the risk of melanoma development.