TLR2 and Parkinson disease: Toll-like receptor 2 and 4 (TLR2 and TLR4) [46], innate immune system proteins upregulated in monocytes and microglia of PD patients, recognize protofibril forms of α-syn, prompting the release of pro-inflammatory signals, neuronal degeneration, and activation of inflammasomes (Fig. 1) [38,40].