NDUFS3 and melanoma: We also measured the levels of Uridine Diphosphate (UDP), Uridine Triphosphate (UTP) and Cytidine Triphosphate (CTP) in A875 and 110 cells with NDUFS3 knockdown or overexpression and found that compared to control cells, there was no significant difference in the levels of UDP, UTP, and CTP in melanoma cells with abnormal NDUFS3 expression (Fig. S4).