CDKN2A and melanoma: CDKN2A on chromosome 9p21 encodes p16INK4a and p14ARF proteins, whose mutation or deletion are closely related to various tumors, such as pancreatic cancer, thymic cancer, melanoma, lung cancer, and others (Sherborne et al., 2010; Nikolaou et al., 2011; Aesif et al., 2017; Cancer Genome Atlas Research Network, 2017; Satpathy et al., 2021; Singhi and Wood, 2021).