In this study, we investigated whether tranilast inhibits the effects of TGF-β-induced EMT in HPMCs by inhibiting the TGF-β/Smad pathway, and whether fibrosis can be attenuated in our established fibrotic tumor model using the gastric cancer cell line MKN-45 in co-culture with HPMCs. This evidence concerns the gene TGFB1 and gastric cancer.