This antibody reacts with a 180 kDa isoform of CD56 (NCAM) expressed in leukocytes. It has been suggested that the antibody MEM-188 could react with rhesus monkey lymphocytes. Reactivity with other NCAM isoforms has not been tested.
CD56 (NCAM, neural cell adhesion molecule) is a transmembrane glycoprotein of immunoglobulin family serving as adhesive molecule which is ubiquitously expressed in nervous system, usually as 120 kDa, 140 kDa or 180 kDa isoform, and it is also found on T cells and NK cells. Polysialic modification results in reduction of CD56-mediated cell adhesion and is involved in cell migration, axonal growth, pathfinding and synaptic plasticity. CD56 is a widely used neuroendocrine marker with a high sensitivity for neuroendocrine tumours and ovarian granulosa cell tumours.