MTHFR and intrahepatic cholangiocarcinoma: Both MTHFR C677T polymorphism and plasma folate concentrations independently were not significantly associated with CIN 2+ after adjusting for all known risk factors of ICC (OR = 1.24, 95% CI = 0.73–2.08, P = 0.420; OR = 0.89, 95% CI = 0.57–1.39, P = 0.609 respectively).