In two large and independent cohorts of patients with iCCA who had undergone tumour resection (n = 137 in one study56; n = 292 in the other119), mutations in KRAS (12–16%) and TP53 (13–20%) were associated with shorter OS and an increased rate of tumour recurrence when compared with patients with IDH1 or IDH2 mutations or an ‘undetermined’ group (with none of the aforementioned mutations)56,119. This evidence concerns the gene IDH2 and neoplasm.