L1 cell adhesion molecule (L1CAM), also known as CD171, is a cell adhesion receptor in the immunoglobulin superfamily, which plays an important role in the development of the nervous system. L1CAM interacts with a variety of ligands. Including axon protein 1, CD9, neurocan, and integrins. The molecule is a type I transmembrane (TM) protein that contains an 1101 aa extracellular region (aa 20-1120) plus a 114 aa cytoplasmic domain (aa 1144-1257). Recent work has identified L1CAM (CD171) as a novel marker for human carcinoma progression, and a candidate for anti-cancer therapy.