The prognostic role of IDH1 or IDH2 mutations in CCA remains unclear: some studies suggested IDH1 or IDH2 mutations as positive prognostic factors, showing an improvement in overall survival (OS) and disease-free survival (DFS) in CCA patients after surgery [83,84,85], whereas other research has not found a significant association between IDH mutations and OS or DFS [86,87,88]. The gene discussed is IDH2; the disease is cholangiocarcinoma.