IDH1 and central nervous system cancer: on a local cohort of grades III/IV glioma (36 IDH‐mutant and 36 IDH‐wildtype) together with a validation TCGA cohort, IDH mutation was significantly linked to lower levels of TIM‐3+ cells and decreased interactions between TIM‐3+ T cells and galectin‐9+ microglia/macrophages, as shown by lower TIM‐3 mRNA expression and IHC staining.