We anticipate that our LRRK2 kinase assay in neutrophils could have utility in future clinical trials to (1) assess LRRK2 pathway activity in Parkinson's patients, (2) identify patients displaying elevated LRRK2 kinase activity and (3) monitor pharmacokinetics and target engagement of administered LRRK2 inhibitors. The gene discussed is LRRK2; the disease is Parkinsonism.