CDKN2A and cancer: p16 function is commonly impaired as a relatively early step in the progression of cancers, including melanoma, attributed to the need for cells to evade senescence for a sizeable lesion to form (Bennett, 2016; Iacobuzio-Donahue et al., 2012; Shain et al., 2018; Witkiewicz et al., 2011).