LRRK2 and Parkinson disease: Data show that LRRK2 gradually, yet significantly increased with age in the PD-LRRK2- (healthy control; R = 0.52, p = 0.0044; Figure 5A) and the PD+LRRK2+ groups (R = 0.57, p = 0.037) but not in the PD-LRRK2+ (Figure 5B) or PD+LRRK2- groups (Figure 5D).