PRKN and parkinsonian-pyramidal syndrome: Some of the central proteins have indeed been implicated in the pathogenesis of PD by independent lines of research, such as genes whose variants are causative of inherited forms of PD (LRRK2, PINK1, PRKN) [73,74,75], are causative of parkinsonian-pyramidal syndrome (FBXO7) [76], and/or are the closest to risk variants for developing PD (BAG3, LRRK2) [8].