MCAM and melanoma: Several multiple marker RT-PCR assays have been demonstrated and proposed as sensitive methods to evidence circulating melanoma cells (CMCs) in peripheral blood of melanoma patients through the detection of one or more melanoma-associated markers (MAMs) of differentiation which include MCAM/MUC18 [2, 9, 10, 15, 21, 31, 34, 43, 44, 51, 53, 57].