Based on our previous work showing that HOXA11 overexpression could accelerate peritoneal dissemination of gastric cancer (GC) cells [1], we examined peritoneal metastatic lesions formed by HOXA11 over-expressed GC cells and its counterparts to determine whether HOXA11 has the ability to form a favorable microenvironment for peritoneal metastasis of GC cells. The gene discussed is HOXA11; the disease is gastric cancer.