We used RT-PCR analysis to characterize the NODAL expression in a panel of human cell lines relevant to cancer and melanoma: melanocytes, non-metastatic melanoma (MNT1), metastatic melanoma (A375M–noted A375 in the rest of the study, FO1, 888 Mel, SLM8), breast cancer (MCF7), and embryonic kidney (HEK293). The gene discussed is NODAL; the disease is melanoma.