LRRK2 and Parkinson disease: LRRK2’s potential role in regulating calcium influx is of considerable interest, given some reports that LRRK2 mutations alter mitochondrial homeostasis (Cherra et al., 2013; Bedford et al., 2016; Verma et al., 2017), and that synaptic mitochondria are a major sink for calcium buffering (see Ryan et al., 2015 for an overview of mitochondrial dysfunction in PD).