TLR4 and Parkinson disease: In addition, in the pathological process of Parkinson’s disease, Toll-like receptor 4 can also be associated with mitogen-activated protein kinases (MAPKs) that regulate cell growth and differentiation, glycogen synthase kinase 3β (GSK3β), AP-1 that regulates oxidative stress and nuclear factor E2 (Nrf2), and other factors that form a cascading pathway.