IDH2 and central nervous system cancer: Previous reports in gliomas showed that IDH‐mut and IDH‐wt tumors exhibited distinct TMEs.[24] To explore whether our IDH‐SG and IDH‐NO have different TMEs, we deconvolved the cellular composition of 54 ICC tumor regions using xCell (Figure S5A, Supporting Information).[38] Notably, in comparison with the IDH‐NO samples, IDH‐SG samples had fewer CD8+ T cells (P < 0.001) and more neutrophils (P < 0.01, Student's t test) (Figure S5B, Supporting Information).