miRNA423-5p regulates cell proliferation and invasion by targeting trefoil factor 1 in gastric cancer cells. TFF1 is a small, secreted protein in the TFF family that has a pivotal role as a motogenic factor in epithelial restitution and cell motility, and as a tumor suppressor gene in the stomach. In this study, we identified TFF1 as a novel target gene of miRNA-423-5p. miRNA-423-5p negatively regulated the expression of TFF1 by binding to its 3'UTR and participated in proliferation/invasion-related processes via a TFF1-dependent manner in gastric cancer cells. Our findings suggested that miR-423-5p may be a novel target for the future development of specific therapeutic interventions for gastric cancer.