LRRK2 and Parkinson disease: While nigral cell loss is consistently observed in LRRK2 PD, α-syn-containing LBs are only found in about half of cases post-mortem; patients also present with ubiquitin-, tau-, or TAR DNA-binding protein 43-positive inclusions, or show nigral degeneration with no aggregate pathology (Zimprich et al., 2004; Rajput et al., 2006; Ujiie et al., 2012).