PD, Parkinson's disease; DNs, Dopaminergic neurons; SN, Substantia Nigra; α‐syn, alpha‐synuclein; RAS, renin‐angiotensin system; Ang II, Angiotensin II; AT1R, Angiotensin II type 1 Receptor; ACE2, angiotensin‐converting enzyme 2; Ang 1‐7, Angiotensin 1‐7; Ang A, Angiotensin A. Here, REN is linked to Parkinson disease.