Studies in gliomas revealed that the IDH‐mutated tumors exhibited a “colder” (non T cell inflamed) TME and a better prognosis in comparison with IDH‐wildtype tumors.[22, 23, 24] Both HCC and ICC studies from the Cancer Genome Atlas (TCGA) reported that the IDH‐mutant subgroup (IDH‐SG) is a distinct molecular subgroup.[19, 25, 26] Here, we showed that IDH1 mutations were enriched in ICC tumors exhibiting a higher degree of ITH. Here, IDH1 is linked to central nervous system cancer.