High levels of ACE2 and TMPRSS2 in neurons, astrocytes, and oligodendrocytes may promote a neuroinvasive predisposition to SARS-CoV-2, and these levels, together with Toll-like receptor 4 activation, predispose patients to α-synuclein aggregation, neurodegeneration, and Parkinson’s disease pathogenesis (108). The gene discussed is TLR4; the disease is Parkinson disease.