The HBL melanoma cell line has previously been demonstrated to express 1000–3000 MSH receptor-binding sites per cell (Ghanem et al, 1988), and A375 and C8161 melanoma cell lines have also been demonstrated to have MSH receptors (Baumann et al, 1997) and MSH binding sites (Sharma et al, 1996). Here, POMC is linked to melanoma.