Disruption of the CX3CL1–CX3CR1 axis leads to dysregulation of microglial and neuronal damage in various animal models of neurodegenerative diseases such as Parkinson’s disease, ischemic stroke, Alzheimer’s disease, and mild traumatic brain injury [63,64,65,66]. The gene discussed is CX3CL1; the disease is early-onset autosomal dominant Alzheimer disease.