ATP5PO and neoplasm: In particular, among the downregulated proteins identified in this study and associated with mitochondrial functions, we cited the voltage-dependent anion-selective channel protein (VDAC2), the electron transfer flavoprotein ETFA and two subunits of ATP synthase (ATP5A1 and ATP5O), as well as several proteins with antioxidant functions localized in the mitochondrial matrix (SOD2 and PRDX3) and, moreover, several enzymes, such as ECHS1, which regulates fatty acid metabolism and is an essential factor in tumor development [38].