Crucial AD-associated genes were identified in each cell type, including RGS1, GRIA1, GRIA3, GRIA4, DLGAP1, MSN, CHL1, DCN, LPAR1, EGFR, GRM5, CAMK2A, APOE, AQP4, GFAP, and CD44, showing potential involvement in AD. Here, AQP4 is linked to Alzheimer disease.