C3AR1 and early-onset autosomal dominant Alzheimer disease: Further, C3a-C3aR signaling may exert distinct effects at different stages after injury (e.g. acute versus post-acute or chronic phase after stroke), in different types of neurodegeneration (e.g. secondary neurodegeneration versus Alzheimer’s disease type neurodegeneration) or at different stages of a specific neurodegenerative condition.