CHCHD2 and Parkinson disease: Genetic evidence validates the correlation between mitochondrial function and PD etiology, since many familial PD genes either directly (e.g., PINK1, PRKN (Parkin), DJ-1, CHCHD2) or indirectly (e.g., SNCA, LRRK2, ATP13A2, FBXO7, VPS13C, VPS35, and GBA1) affect mitochondrial function [30].