PCA in two independent cohorts for whom core AD biomarkers and nine CSF inflammatory protein levels were previously and independently measured (Supplementary Methods; Table S5) replicated PCs for core AD, sTNFR1, IL-10, and IL-7/TNF-α PCs, but sTREM2 (measured using a commercially available assay distinct from the two used in ADNI) became a member of the sTNFR1 PC. Here, IL10 is linked to Alzheimer disease.