Because, EpCAM antigen is not expressed by all tumors, we divided malignant patients into two groups according to their etiology: 1) carcinoma (n = 44) known to generally express EpCAM, and 2) non-carcinoma (n = 27, mesothelioma, melanoma, lymphoma and sarcoma) generally not expressing EpCAM. The gene discussed is EPCAM; the disease is mesothelioma.