Loss of function of both CDKN2A and its tandemly linked gene CDKN2B, which encodes p15INK4b, another regulator of the Rb pathway (Hannon & Beach, 1994), have been implicated in a variety of cancers from central nervous system (CNS) tumors, including schwannomas (Ali et al., 2021; Almeida et al., 2008; Cancer Genome Atlas Research, 2008; S. Zhang et al., 1996) pancreatic cancer, renal cancer, and melanoma (Goldstein et al., 2006; Jafri et al., 2015; McNeal et al., 2015; Patel et al., 2020; Tu et al., 2018). The gene discussed is CDKN2A; the disease is melanoma.