The B159 monoclonal antibody specifically reacts with CD56. CD56 is a heavily glycosylated protein that is present on a subpopulation of peripheral blood large granular lymphocytes which demonstrate natural killer activity. CD56 is also expressed on a subset of T cells but is not expressed on myeloid cells, erythrocytes or B cells. This antigen is a pan-NK-cell marker. CD56 is virtually identical to an isoform of the neutral cell adhesion molecule (NCAM), a structure mediating homotypic and heterotypic cell-cell interactions. Synonyms: NCAM1, NCAM-1, Neural cell adhesion molecule 1, NCAM, MSK39