APOE and Parkinson disease: Besides biomarkers for amyloid positivity (pTau217, pTau231, GFAP, APOE4), we found elevated plasma levels of proteins related to inflammatory and oxidative stress processes in neurodegeneration (e.g., peroxiredoxin 6 [47], malate dehydrogenase 1 [48], superoxide dismutase 1 [49]), proteins related to LATE (TARDBP and pTDP43-409 [50]), proteins related to dementia with Lewy bodies and Parkinson’s disease (alpha synuclein), and Huntington’s disease (huntingtin [51]), among others.