CX3CR1 and early-onset autosomal dominant Alzheimer disease: CX3CR1 signaling is known to regulate microglial phagocytosis in other contexts, such as synaptic phagocytosis during development (Milior et al., 2015; Paolicelli et al., 2011), and amyloid plaque clearance in Alzheimer's disease models (Lee et al., 2010; Liu et al., 2010).