We further analyzed the interacting ligand-receptor pairs among the five immune cell subsets in the AD samples (S9 Table), in which we identified 50 important ligand-receptor pairs distributed in nine signaling pathways, including MIF, GALECTIN, RESISTIN, ANNEXIN, IL16, TNF, PARs, BAFF, and APRIL pathways. Here, TNFSF13B is linked to Alzheimer disease.