IL15 and Alzheimer disease: Most genes with higher expression in microglia from older subjects, including IL15 and the candidate AD risk genes MS4A6A, MS4A4A, NME8, and GPR141, trended toward elevated expression in AD relative to control microglia; conversely, genes with lower expression in microglia from older subjects, like CECR2, tended to be reduced in AD microglia (Figures 5A and 6A).