In addition to use as pharmacodynamic readouts, several studies have measured pS1292-LRRK2 and phosphorylated Rab proteins in PD patient samples to test the hypothesis that LRRK2 kinase activity is elevated in all or a subset of PD (Dzamko et al., 2013; Fraser et al., 2016a; Atashrazm et al., 2018; Fan et al., 2018; Lis et al., 2018). Here, LRRK2 is linked to Parkinson disease.