GPNMB and Parkinson disease: We found 15 proteins had significantly different protein levels between controls and cases, controls and prodromal samples, and/or control and mutation carriers (Supplementary Fig. 4 and Supplementary Table 5), which included the ones predicted by the FUSION approach: HLA-DQA2, GRN, GPNMB, ENTPD1, ITBG2, and TMEM106A were dysregulated in PD cases, as well as even at the prodromal stages.