In summary, the antitumor effect of gramicidin on gastric cancer cells was preliminarily explored, in which gramicidin may inhibit cell proliferation and induce G2/M cell cycle block by down-regulating the FoxO1 and cyclinD1 while down-regulating tumor suppressor genes Bcl-2 to induce apoptosis. This evidence concerns the gene FOXO1 and gastric cancer.