MITF and melanoma: High-OXPHOS MBMs also had higher expression of MITF, a lineage-specific transcription factor that regulates PGC1α in melanoma (P.adj = .0169; Figure 2A).9,11,23 Previously, we observed in human melanoma cell lines that MITF activity, and thus PGC1α expression, are regulated in melanoma by mTOR.9 Consistent with that result, GSEA-P analysis of High- versus Low-OXPHOS MBMs demonstrated significant enrichment (FDR q-val < 0.0001) of genes regulated by the mTORC1 signaling pathway in High-OXPHOS tumors (Figure 2B).