C5AR1 and early-onset autosomal dominant Alzheimer disease: Research has proved that C5AR1 (also named CD88) played an important role in the regulation of inflammation and neurocognitive functions in ischemic stroke, Alzheimer’s disease, malaria, and neuropathic pain (Moriconi et al., 2014; McDonald et al., 2015; Brandolini et al., 2019).