COX4I1 and cancer: Further, c-MYC upregulates OxPhos in several cancer cell lines because it (i) increases the mRNA content of several genes involved in mitochondrial biogenesis (MIEFs, TFAM, mitoRBs), mitochondrial stability (BCS1L, COX15), and OxPhos (COX4, PDH, FH, ATPS, GA, glutamine transporters SLC38A5 and SLC1A5); (ii) increases the activity of GA; and (iii) enhances mitochondrial acetyl-CoA levels, indicating active pyruvate, ketone body, glutaminolysis, and FFA oxidation versus nonactivated c-MYC cells (Figure 2A, Table 3).