S100A9 and Parkinson disease: Recently, in our latest proteomic work carried out on saliva samples, PRDX1, TPI1, thioredoxin (TXN), phosphoglycerate mutase 1 (PGAM1), and correlated forms of superoxide dismutase (SOD2), peroxiredoxin-6 (PRDX6), protein S100-A9, heat shock proteins (HSPB1, Hsp90-beta), and proteasome (subunits alpha and beta), were revealed to be overexpressed in patients with advanced PD when compared to periodontally healthy subjects [66].