MCAM and melanoma: In this system, ferrofluids coated with CD146 Abs were used to immunomagnetically enrich CTCs, and a fluorescent labeled high molecular weight melanoma-associated antigen (HMW-MAA, chondroitin sulfate proteoglycan 4) specific Ab was utilized for CTC detection in melanoma, as well as CD45 and CD34 Abs for exclusion of white blood cells and endothelial cells.