The invention relates to methods for diagnosis and prognosis of gastric cancer. The approach described herein can distinguish intestinal-type gastric cancer (G-INT) from diffuse-type gastric cancer (G-DIF). The genomic expression signatures of G-INT and G-DIF define two major sets of genes. A diagnosis of gastric cancer G-INT and G-DIF can be made on the basis of the expression levels of these genes. This can lead to a better prognosis and treatment of gastric cancer.
