ACD and melanoma: Four genes belonging to this class have been implicated in familial melanoma susceptibility: (1) TERT (Telomerase Reverse Transcriptase); (2) POT1 (Protection of Telomeres 1); (3) ACD (ACD Shelterin Complex Subunit and Telomerase Recruitment Factor); and (4) TERF2IP (TERF2 Interacting Protein) [44,45].