MCAM and melanoma: Fifth, METCAM may mediate hematogenous spreading of melanoma cells, which had been implicated by its expression in endothelial cells, as well as in malignant melanoma cells [48], further shown to be present in the junctions of endothelial cells [49, 50] and essential for tumor angiogenesis in at least three tumor cell lines [51] and human prostate cancer LNCaP cells [52].