APP and Alzheimer disease: Two microglial states were found to be present in an amyloid precursor protein (APP) knock-in mouse model of Alzheimer’s disease (AD): ARM, which is similar to DAM and IFN response microglia expressing Ifit2, Ifit3, IFN regulatory factor 7 (Irf7), IFN-induced transmembrane protein 3 (Ifitm3), and 2′-5′ oligoadenylate synthetase-like 2 (Oasl2) [39].