In turn, during some harmful events related to the nervous system, such as TBI, I/R injury, cognitive impairment and neurodegenerative diseases (Chen et al. 2018; Wang et al. 2018b; Kang et al. 2020; Jiang et al. 2019; Wang et al. 2020), FGF21 can also exert certain protective effects. The gene discussed is FGF21; the disease is neurodegenerative disease.