MUC5AC and adenocarcinoma: Focusing on the histogenesis of the gastric diffrentiated adenocarcinoma, the results of mucin expressions of SMCa revealed that gastric well-differentiated adenocarcinoma should not derive from the intestinal metaplasia with no remnant gastric original tubules (the tubules exchanged perfectly by intestinal metaplasia), because all of SMCa lesions had the gastric phenotypic mucin.