In particular, recent papers have focused the attention only on the roles of extracellular TLR, such as 2 and 4, in the pathogenesis of PD [20,21], never looking to the involvement of the other TLRs, such as the intracellular TLR7, 8, and 9 in PD etiology. The gene discussed is TLR7; the disease is Parkinson disease.