The best characterised one is CD166/ALCAM (for Activated Leukocyte Cell Adhesion Molecule), a 100 kDa adhesion molecule of the immunoglobulin superfamily (IgSF) with a broad tissue distribution including activated mature T and B lymphocytes, melanoma cells, fibroblasts, bone marrow cells, endothelial cells, cerebral cortex, and epithelial cells from skin, thymus, digestive tract, pancreas, liver, and kidney [35,36]. Here, ALCAM is linked to melanoma.