STAT3 and cancer: This is the first study to investigate the relationship between HOXA11 and cancer stemness in peritoneal metastasis of gastric cancer, and we have identified a novel positive feed-back loop of HOXA11/Stat3-dependent stemness of gastric cancer cells supporting peritoneal metastasis that can be targeted by BBI608 (Napabucasin), offering hope for new cancer therapies.