Abstract: Objective Inhibitor of growth 1(ING1)gene has been identified as a novel candidate of tumor suppressor gene.Over-expression of ING1 plays well-established roles in numerous cell processes,including DNA repair and cell apoptosis.Our study is to investigate the clinical significances of expression of ING1 in colorectal cancer(CRC).Methods The mRNA level of ING1 in 82 matched samples comprising primary CRC and paired non-cancerous mucosa were detected and compared by quantitative RT-PCR.Then the correlations of mRNA level of ING1 with the clinicopathological characteristics and prognosis of patients with CRC were analyzed.Results (1)In the same matched tissues,the expression level of ING1 was significantly higher in normal tissues than that in cancer tissues.(2)mRNA expression of ING1 was associated with certain clinical-pathologic variables such as tumor infiltrating level,lymphatic metastasis,distant metastasis and advancing TNM stage.(3)We obtained the expression levels ratio of cancer tissue and normal tissue and found the lower ratio has a lower Disease-Free Survival(DFS)(P＜0.0001).(4)ING1,as a candidate of tumor suppressor gene,remained a statistically-significant prognostic marker in the Cox regression analysis.Conclusion Down-regulation of ING1 may be correlated tightly with the occurrence and progression of sporadic colorectal cancer.Its expression level can be used to predict prognosis of CRC.