CD274 and glioma: At present, immunotherapy for glioma is the most agreeable option, and a lot of related research is underway, such as programed cell death 1 ligand 1 (PDL-1) (Mathios et al., 2016), indoximod (IDO) (Lukas et al., 2019), and cytotoxic T lymphocyte antigen 4 (CTLA-4) (Fong et al., 2012).