DHFR and melanoma: Of note, the set of genes highly expressed in more-aggressive melanomas includes many novel genes with reported functional roles in cell cycle regulation and proliferation such as ZWINT, CDCA2, NCAPH, NCAPG, NCAPG2, PBK, NUSAP1, BIRC5, ESCO2, HELLS, MELK, and CDKN2C[20]–[31] as well as genes that are involved DNA replication and repair processes including GINS1, GINS4, RAD54L, TYMS, and DHFR[32]–[34] (Table 1).