The other three key genes, UBC, PTEN, and CCND1, were also well studied in melanoma (Roh et al., 2016; Donigan et al., 2017; Uguen et al., 2017; Mu and Sun, 2018; Zhang et al., 2018; Zhu et al., 2018; Chen et al., 2019; Giles et al., 2019). Here, UBC is linked to melanoma.