ACE and Parkinson disease: RAS has two main pathways: the classical pathway, which includes angiotensin I (AngI), AngII, angiotensin‐converting enzyme (ACE), Ang type 1 receptor (AT1R), and Ang type 2 receptor (AT2R), that has a neuro‐detrimental effect on PD neuropathology, and the nonclassical pathway, which includes angiotensin‐converting enzyme 2 (ACE2)/Angiotensin 1–7 (Ang1–7), that has a neuroprotective effect against different neurological disorders, including PD.