MCAM and neoplasm: Among the possible targets, Melanoma Cell Adhesion Molecule (MCAM)/CD146 represents a useful tool since it has been found expressed by a subpopulation of BM human stromal cells that have a pivotal role in the establishment of the HSC niche (26) and are implicated in resettlement, survival and growth of tumor cells in human BM niches recreated in vivo (27–29).