C3 and nervous system disorder: The reactive astrogliosis may secrete various cytokines/chemokines and transform into A1 neurotoxic astrocytes to influence the local inflammatory microenvironment, which is supported by the evidence that astrocytic complement C3 is linked to various neurological diseases (Yun et al., 2018; Clark et al., 2019; Li et al., 2022; Stym-Popper et al., 2023).