Neural Cell Adhesion Molecule (NCAM, also the cluster of differentiation CD56) is a homophilic binding glycoprotein expressed on the surface of neurons, glia, skeletal muscle and natural killer cells. NCAM has been implicated as having a role in cell–cell adhesion, neurite outgrowth, synaptic plasticity, and learning and memory. ==Forms, domains... Found on http://en.wikipedia.org/wiki/Neural_cell_adhesion_molecule