Increased protein levels of TLR2 and TLR4 have previously been reported in the substantia nigra [15, 67], and the caudate/putamen of PD compared to control brains [16], and in addition, these receptors are upregulated in peripheral blood mononuclear cells of PD patients compared to controls [16, 74]. The gene discussed is TLR4; the disease is Parkinson disease.