NOX4 and melanoma: On the other hand, the top downregulated genes formed 4 subgroups and were related to melanogenesis (Wnt5a, Mitf, Pomc, Mc1r, Kit), melanoma (Fgf9, Fgf12, Fgf2), MAPK signaling pathway (Ncam1, Prkcb, Map3k4, Pla2g4a, Mapk14, Mapk11), and aging (Tgfbr1, Il6, Nox4).