IDH1 and gastric cancer: In GC, univariate analysis showed that low IDH1-R132H expression (HR, 0.634, P=0.001) was correlated with poor OS, along with prognostic factors that were reported previously, including differentiation (HR, 1.639, P<0.001), tumor stage (HR, 1.529, P<0.001), tumor size (HR, 1.765, P<0.001), lymph node metastasis (HR, 1.642, P<0.001), distant metastasis (HR, 3.188, P<0.001), preoperative CEA levels (HR, 2.279, P<0.001), and CA19-9 levels (HR, 2.422, P<0.001).