In particular, KRAS mutation has been reported as a representative factor indicative of poor prognosis in ICC [12–14], and our patients with mutated KRAS showed significantly worse survival compared to those with wild-type KRAS. Regarding glucose metabolism, Warburg discovered that, even in the presence of oxygen, cancer cells undergo aerobic glycolysis rather than the normal oxidative phosphorylation. The gene discussed is KRAS; the disease is intrahepatic cholangiocarcinoma.