Knockdown of DNMT1, DNMT3a, and DNMT3b in Neuro2a cells revealed that it is likely that at least two or all DNMTs functionally cooperated in the activation of DNA methylation after glutamatergic excitotoxicity and that zebularine prevented glutamatergic excitotoxicity in Neuro2a cells and primary cortical neurons by inhibiting DNA methylation in neurons after cerebral ischemia-induced neuronal cell death (Asada et al., 2022). The gene discussed is DNMT3A; the disease is brain ischemia.