LRRK2 and Parkinson disease: In LRRK2 patient induced pluripotent stem cell derived DA neurons, LRRK2 phosphorylation of auxilin led to decreased auxilin levels and clathrin binding, resulting in accumulation of oxidized dopamine and α-synuclein overexpression.22 Whether loss-of-function mutations in auxilin can also trigger PD through these mechanisms is unknown.