LRRK2 and Parkinson disease: It was claimed that 8-hydroxy-2′-deoxyguanosine (8-OHdG), 8-isoprostane (8-ISO), 2-hydroxybutyrate, mtDNA, lamp2, and neopterin may differentiate between healthy LRRK2 carriers and LRRK2 PD subjects; and soluble oligomeric α-synuclein, 8-OHdG, and 8-ISO might differentiate healthy LRRK2 carriers from control subjects (Aasly et al., 2012, 2014; Shi et al., 2012; Podlesniy et al., 2016; Vilas et al., 2016; Loeffler et al., 2017; Wang et al., 2017; Ichinose et al., 2018; Klaver et al., 2018).