PIK3R1 and Alzheimer disease: In the present study, we identified thirteen immune hub genes (CD86, HSPA4, FOS, GRB2, KRAS, PTPN11, PTPRC, TLR2, PIK3R1, IGF1, JUN, HSP90AA1, and STAT3) associated with Braak stages in AD through WGCNA and the cytoHubba plugin.