IDH1 and central nervous system cancer: Zeng et al. discovered that patients with IDH1-mutant gliomas may harbor a TME characterized by elevated levels of HLA-DQA2, Homeobox A3 (HOXA3), and Circulating serum amyloid A2 (SAA2), which lead to the suppression of M1 macrophages and CD8+ T cells, and are more sensitive to ICB therapy [86].