Immunohistochemical and immunoelectron microscopic studies were performed using specific monoclonal antibodies to transforming growth factor(TGF)-¥al, ¥a2 to determine their presence and cellular localization in human gastric adenocarinoma cells. Specific immunostaining was clearly detected in the cytoplasm of the neoplastic cells. The TGP-¥al, -¥a2 expression in the gastric adenocarcinoma is closely related to the depth of invasion, the degree of invasiveness and the presence of metastasis. In immuno-electron microscopy by 10nm gold particles, there are TGF¥a1, -¥a2 lacalized predominantly in the cytoplasm of the neoplastic cells. The gold particles were present within the secretory granules. The TGF-¥al, ¥a2 are not present in the cytoplasmic organells such as Golgi apparatus, mitachontria or rough endoplasmic reticulum.