ACE2 and Parkinson disease: Although the expression levels of ACE2 in the brain of PD patients is decreased due to degeneration and loss of dopaminergic neurons, there are still evidences that SARS-CoV-2 can invade CNS of PD patients and further aggravate the CNS injury and clinical situations (Achbani et al., 2020; Pavel et al., 2020; Victorino et al., 2020).