While it has not been ruled out that the RGS10 deficiency we observed in PD could be due to inherent differences in RGS10 expression in the population which might predispose certain individuals to heightened inflammatory responses, activation of TLR4 signaling cascades has been shown to inhibit RGS10 expression [15, 21], and PD patients reportedly have higher systemic levels of LPS, the classic TLR4 ligand, in their blood [66] along with elevated levels of circulating proinflammatory cytokines [67]. Here, TLR4 is linked to Parkinson disease.