We co-transfected gastric cancer cells with the following synthetic RNAs: (1) anti-miR-control and control siRNA, (2) anti-miR-181a-5p and control siRNA (3) anti-miR-control and MEG2 siRNA, and (4) anti-miR-181a-5p and MEG2 siRNA. This evidence concerns the gene PTPN9 and gastric cancer.