Neural cell adhesion molecule (NCAM (CD56))

Neural cell adhesion molecule (NCAM, CD56) is a cell surface glycoprotein of the immunoglobulin superfamily engaged in both homophilic (NCAM–NCAM) and heterophilic adhesion. It is abundantly expressed on neurons, glia, skeletal muscle, and is the archetypal marker for human natural killer (NK) cells, as well as certain subsets of T cells and dendritic cells[1][2][3][5]. There are three major isoforms—NCAM-120 (GPI-anchored), NCAM-140, and NCAM-180—with overlapping but distinct tissue distributions and signaling capacities[2][5]. Functionally, CD56 mediates cell–cell and cell–matrix interactions, migrating, and activating cytotoxic lymphocytes, and is implicated in neural development and plasticity as well as immune response. In disease, CD56 serves both as a diagnostic biomarker and a target in neuroendocrine tumors, hematological malignancies, and pathological conditions involving impaired NK cell function[1][2][6]. This molecule is a member of the immunoglobulin superfamily, critical for mediating cell adhesion, migration (including NK cell movement and polarity), and integrating immune and neural signaling pathways. It plays a direct and indirect role in immune surveillance, tumor progression, and is a focus of evolving therapeutic strategies[1][4][5][9].

Other names

NCAMN-CAMLeu-19NKH1cluster of differentiation 56

Antibody-dependent cell-mediated cytotoxicity (ADCC) via anti-CD56 antibodies. Direct tumor targeting with antibody-drug conjugates (e.g., lorvotuzumab mertansine). Pharmacologic modulation of NK cell function (by upregulating or blocking CD56 signaling).