PPARGC1A and lip and oral cavity carcinoma: Enhancement of the enzymatic activity of SIRT1 leads to increased expression of peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC1α) and mitochondrial dynamics protein 18 (MTP18); consequently, this promotes mitochondrial biogenesis and fission, thereby preserving the mitochondrial population in oral cancer cells [36].