Peroxisome proliferator-activated receptor gamma coactivators 1-α/β (PGC1α/β) coactivate peroxisome proliferator-activated receptors (PPARs), estrogen-related receptors (ERRs) and nuclear respiratory factors (NRFs) to orchestrate expression of proteins of FA utilization and OXPHOS during mitochondrial biogenesis. PGCs also drive mitochondrial transcription factor A (TFAm) expression to regulate protein/RNA expression and replication of mtDNA. Mitochondrial dynamics are balanced by mitochondrial fission, driven by dynamin-related protein 1 (DRP1) and fission 1 (FIS1), and mitochondrial fusion, promoted by mitofusin 1/2 (MFN1/2) and optic atrophy 1 (OPA1). Removal of mitochondria is accomplished by autophagy of mitochondria (i.e., mitophagy).