We found that that TLR4 levels were greater in the SN of patients with PD compared with age-matched controls (Fig. 1c,d), indicating that there is indeed an increase in TLR4 expression in PD brains, even though the total levels of microglia were not significantly different between patients with PD and age-matched controls (Fig. 1c). The gene discussed is TLR4; the disease is Parkinson disease.