CD56 + NCAM1 (Cluster of differentiation 56 + neural cell adhesion molecule 1)

CD56 is a member of the Ig super family and comprises five Ig-like domains and two extracellular fibronectin-type III domains. It is expressed as three major isoforms within the nervous system, on NK cells, and a specific set of T-cells. CD56+ NK and T-cells are unique in their ability to mediate cell-mediated cytotoxicity against certain tumor cell targets without MHC restriction. Other CD56 physiological functions include: mediating cell adhesion, triggering neurite extension and migration, and brain synapse formation.

p14 ARF is an Important Tumor Suppressor

The p14ARF (Alternative Reading Frame) tumor suppressor is a protein product of the alternative reading frame (ARF) of the human INK4a locus which regulates a series of cell cycle regulatory proteins to promote cell cycle arrest in response to abnormal hyper-proliferative growth stimuli. p14ARF alterations are common in human cancers and, when inherited, confer susceptibility to cutaneous melanoma (1).