APOE and amyloidosis: Single-cell RNA-seq of amyloidosis mouse models revealed that a microglial subpopulation transitions from a homeostatic state to an activated state termed ‘disease-associated microglia’ or ‘activated response microglia’4,55, with increased expression of microglial activation genes (including APOE, AXL, TREM2 and CD74)53–56 that are crucial regulators of phagocytic processes81–84.