A recent study analyzed PD-1+ T cell infiltration and also PD-L1 tumor cell expression in 57 IDH mutant and 117 IDH wildtype gliomas and found that IDH wildtype HGG gliomas display more prominent PD-1+ T cells and higher PD-L1 expression when compared to IDH mutant LGG cases25. Here, IDH1 is linked to central nervous system cancer.