NLN and Parkinson disease: By analyzing the GTEx RNA-seq database49 and a published single-cell RNA-seq dataset50, we found that the transcript level of Neurolysin is increased in substantia nigra where DA neurons are enriched during normal human aging (Supplementary Fig. 4a), but reduced in DA neurons derived from induced pluripotent stem cell (iPSC) carrying the GBA-N370S PD risk variant compared to the healthy control50 (Supplementary Fig. 4b).