TLR2 and Parkinson disease: First, a C-to-T single nucleotide polymorphism in TLR2 rs3804099  is associated with increased PD risk in a Han Chinese population, especially among those with late-onset PD [44], whereas a recent study utilising a Caucasian subset of the Parkinson’s Progression Markers Initiative (PPMI) cohort reported that TC heterozygotes and minor CC homozygotes of TLR2 rs3804099 have  significantly increased PD risk [45], indicating possible geographical or ethnic differences regulating the link between TLR2 polymorphisms and PD.