Laminin is a major basement membrane component synthesized by epithelial and endothelial cells. It is involved in embryonic differentiation, morphogenesis, cell migration, neurite growth and tumor metastasis. To investigate the role of laminin in tumor metastasis, we have used 10 cell lines derived from Korean stomach and colorectal carcinoma patients. The expression of laminin gene was analyzed by Northern and slot blot techniques. Elevated level of laminin mRNA was found in stomach cancer cell line, SNU-16 and colorectal cancer cell line, SNU-67. The high level of laminin expression found in these cell lines may be associated with the metastatic state of these tumors. In addition, we have analyzed the expression of chromogranin A gene on these cell lines using the same experimental techniques. Chromogranin A is a protein present in the secretory granules of endocrine and neuronal cells and can be used as marker for neuroendocrine lineage. The fact that a previously unrecognized subgroup of stomach and colorectal carcinomas has neuroendocrine features will improve tumor classification, diagnosis and treatment. Of the tested 10 tumor cell lines, SNU-16 (stomach), SNU-67 (colon), and SNU-C2A (colon) express chromogranin A gene. Thus these cell lines might be of neuroendocrine origin. Further, it seems reasonable that some subsets of colon and stomach adenocarcinomas might have neuroendocrine features.