Gastric cancers have been known to secrete the proangiogenic cytokine VEGF in vitro and in vivo. Tumor VEGF expression is correlated with the severity of disease in patients with gastric cancer and some authors have suggested using circulating VEGF as a prognostic factor or tumor marker.In addition to producing proangiogenic cytokines, recent data demonstrate that tumors can produce antiangiogenic cytokine as well. It has been suggested that, in humans, the generation of antiangiogenic compounds in the presence of a primary tumor suppresses the growth of distant metastases. This phenomenon has been demonstrated in mice and in patients with clear cell renal cancer, breast cancer, and colorectal cancer. However, the presence of endogenous antiangiogenic cytokines in patients with gastric cancer has not been reported.