NCAM1 and neoplasm: The neoplastic natural killer (NK) cells usually harbor the Epstein-Barr virus (EBV) with a latent viral infection pattern type II; they often have a cytoplasmic CD3<i>ε</i><sup>+</sup> and surface CD3<sup>-</sup>, CD2<sup>+</sup>, and CD56<sup>+</sup> immunophenotype, and they show complex genetic abnormalities affecting multiple tumor suppressor genes and oncogenes.