In addition, complement C3 is characteristic of neurotoxic “A1” astrocytes (Liddelow et al., 2017) and its production in astrocytes is upregulated in aging and in disease (Boisvert et al., 2018; Propson et al., 2021) and in experimental epilepsy (Wei et al., 2021; Vasanthi et al., 2023). The gene discussed is C3; the disease is epilepsy.