Several PD-related substances, such as α-Synuclein, Parkin, PTEN-induced putative kinase 1 (PINK1), DJ-1 and Leucine-rich repeat kinase 2 (LRRK2), are involved in mitochondrial function in DA; therefore, loss or mutation of these substances causes cell death (Um et al., 2009; Fernández-Moriano et al., 2015; Requejo-Aguilar and Bolaños, 2016). Here, LRRK2 is linked to Parkinson disease.