Our immunohistochemical finding obtained from archived clinical specimens, that Akt pathway tended to be activated (phosphorylated) in the liver metastasis in HER2-overexpressing gastric cancer patients, while still preliminary, suggests that HER2 overexpression, together with constitutive activation of the PI3K/Akt pathway, may be useful predictive markers for gefitinib sensitivity in gastric cancers. The gene discussed is ERBB2; the disease is gastric cancer.