IDH1 and intrahepatic cholangiocarcinoma: Although the expression of IDH1 was largely increased in ICC patients (8 negative vs. 105 positive), IDH1 level was not associated with mortality (HR = 1.05; 95% CI: 0.42–2.61) or disease recurrence (HR = 1.29; 95% CI: 0.52–3.2).