Several human cancer cell lines have been shown to produce ET-1 with autocrine/paracrine growth factor functions (Kusuhara et al, 1990; Shichiri et al, 1991), and ET-1 has been implicated in metastasis of colon cancer (Shankar et al, 1998; Asham et al, 2001) and as an apoptosis survival factor in endothelial cells (Shichiri et al, 1997), smooth muscle cells (Wu-Wong et al, 1997) and fibroblasts (Shichiri et al, 1998). This evidence concerns the gene EDN1 and malignant colon neoplasm.