ROR2 overexpression inhibited the proliferation of AGS gastric carcinoma cells. The (A) mRNA and (B) protein expression levels of ROR2 in AGS cells transfected with the pcDNA3.1-ROR2 plasmid were examined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. (C) MTT assays were performed to determine the proliferation capacity of AGS cells transfected with the pcDNA3.1-ROR2 plasmid. AGS cells transfected with the blank vector and non-transfected AGS cells were used as controls. (D) MTT assays were performed to determine the proliferation capacity of AGS cells transfected with the pcDNA3.1-ROR2 plasmid in the presence or absence of the ROR2 ligand, Wnt5a. **P<0.01, vs. AGS. ROR2, receptor tyrosine kinase-like orphan receptor 2; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; OD, optical density.