AIM: Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β(TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still unknown. Thus we attempted to investigate the effect of TGIF on biologic behaviors of gastric carcinoma cells. METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly expressing clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colony-formation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy. Tumorigenicity of the transfectant cells was also analyzed. RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cellular organelles of cells transfected with TGIF were richer than those of vector control or parental cells. Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also had no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-β mediated growth inhibition. CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β. AIM: Transforming growth interacting factor (TGIF) is an inhibitor of both transforming growth factor β (TGF-β) and retinoid signaling pathways. Moreover, the activation of MAPK pathway can prolong its half-life. However, its role in carcinogenesis is still METHODS: Gastric carcinoma cell line, SGC-7901, was stably transfected with plasmid PcDNA3.1-TGIF. Western blotting and cell immunohistochemistry screening for the highly The clone of TGIF were employed. The growth of transfected cells was investigated by MTT and colony-formation assays, and apoptosis was measured by flow cytometry (FCM) and transmission electron microscopy. Tumorigenicity of the transfectant cells was also analyzed. RESULTS: TGIF had no effect on the proliferation, cell cycle and apoptosis of SGC-7901 cells, but cells organelles of cells transfected with TGIF were richer than those of vector con Its clones were smaller than the control ones in plate efficiency, and its tumor tissues also have no obvious necrosis compared with the vector control or parental cells. Moreover, TGIF could resist TGF-beta mediated growth inhibition. CONCLUSION: TGIF may induce differentiation of stomach neoplastic cells. In addition, TGIF can counteract the growth inhibition induced by TGF-β.