TREM2 and Parkinson disease: To determine the pharmacokinetics and pharmacodynamics of Nilotinib in individuals with PD, we designed a physiologically based population pharmacokinetic/pharmacodynamic (popPK/PD) study and measured plasma and CSF concentration of Nilotinib as well as DOPAC, HVA, total and oligomeric alpha‐synuclein and TREM2 levels.