Treatment with paeoniflorin at a dose of 5 mg/kg after SAH (twice daily, i.p., 3 days) has been reported to inhibit SAH-induced brain edema, blood-brain barrier impairment, neurological deficits, and walking disability in rats by 1) reducing levels of reactive oxygen species, MDA, and 3-nitrotyrosine, 2) increasing the levels of SOD and the activity of glutathione peroxidase (GSH-Px) and catalase in a nuclear factor erythroid-related factor 2 (Nrf2)-dependent manner, and 3) inhibiting the production of pro-inflammatory cytokines in the cortex (Wang et al., 2020) (Figure 2B). The gene discussed is NFE2L2; the disease is brain edema.