Colocalization analysis confirmed that nine of these proteins (ARSA, EHBP1, FCGR2A, GGH, GPNMB, HDHD2, DNAJB4, HAVCR2, and PDCD1LG2) shared a common causal variant with PD onset (PPH4 > 0.8; Table S6, Figure 4B). Here, HDHD2 is linked to Parkinson disease.