IDH1 and glioblastoma: Interestingly, recent NGS data revealed heterogeneity in immune infiltrates,60,61,63 regional differences in macrophage activation,56,66 and utilization of different immunosuppressive mechanisms within the major GBM subtypes.67 In a detailed fluorescence-activated cell sorter-based study, Amankulor and colleagues demonstrated decreased CD45+ immune cell infiltration in human IDH1 mutant tumors as compared to wild-type tumors.68 This included significant reductions in microglia, tumor-associated macrophages, T cells, B cells, and dendritic cells.