Conversely, severe mtDNA CI mutations are found in indolent, low-proliferative oncocytic tumors8,9, i.e., neoplasms characterized by cells accumulating mostly dysfunctional, aberrant mitochondria and displaying scarce vasculature associated with destabilization of Hypoxia Inducible Factor-1 alpha (HIF-1α), the main promoter of vasculogenesis, glycolysis, and survival in hypoxic environment10. This evidence concerns the gene HIF1A and neoplasm.