High levels of complement molecules, including C3, are consistently found in brain biopsies derived from patients with different epilepsies with drug-resistant seizures such as focal cortical dysplasia (FCD) (Wyatt et al., 2017; Gruber et al., 2022), tuberous sclerosis complex (TSC) (Boer et al., 2008), and temporal lobe epilepsy (TLE) (Aronica et al., 2007). The gene discussed is C3; the disease is epilepsy.