Even mitochondrial biogenesis is weakened in AD [73,74]: the leading regulator of mitochondrial biogenesis, peroxisome proliferator activator receptor gamma-coactivator 1α (PGC-1α), is downregulated at the mRNA and protein levels, particularly in human AD hippocampus tissues and in cell models overexpressing the Swedish APP mutation [75]. The gene discussed is PPARGC1A; the disease is Alzheimer disease.