TACR3 and Parkinson disease: We chose to study the TACR3 gene polymorphism rs3733631, because TACR3 endogenous ligand, neurokinin B, by increasing blood flow (anatomoclinical feature of rosacea), is involved in the pathophysiology of (a) Parkinsonism (frequently coexists with rosacea) and (b) hot flushes in menopausal women (clinically similar to rosacea vasomotor crises).