In order to verify the interaction between gastric cancer cell-derived IL-lα and stromal cells in the tumor microenvironment, we determined the effect of IL-1RA by assessing the inhibition of gastric cancer cell-derived IL-1α and downregulation of HUVEC migration in a co-cultivation system consisting of gastric cancer cells and HUVECs. The gene discussed is IL1A; the disease is gastric cancer.