As an example, the brain-enriched miRNAs miR-7 and miR-153 have important roles in the regulation of α-Syn expression prompted by mitochondrial ROS-mediated action, both miRNAs can synergistically down-regulate α-Syn expression (Junn et al., 2009; Thompson et al., 2016; Xie and Chen, 2016) and may be associated with the familial form of PD through deregulation of the leucine-rich repeat kinase 2 (LRRK2) gene (Gehrke et al., 2010). The gene discussed is LRRK2; the disease is Parkinson disease.