And growing evidence reveals that impaired PGC-1α expression and/or function is a frequent underlying cause of mitochondrial malfunction in neurological illnesses like PD, HD, and ALS (Johri et al., 2013; Bayer et al., 2017; Yang et al., 2020; Piccinin et al., 2021). The gene discussed is PPARGC1A; the disease is Parkinson disease.