CD57 (Cluster of Differentiation 57) is an adhesion molecule on cell surfaces. The epitope is expressed predominantly on natural killer cells (NK cells) and in a subgroup of T cells, and is most frequently found in the germinal centers of lymph nodes, tonsils and spleen.
The antibody detects NK cells and follicular central cell lymphomas, which often contain many NK cells. CD57 reacts with neuroendocrine cells and their derived tumors, and is a marker for a variety of cell types in non-lymphoid tissues, including neurofibromas, ganglioneuromas and prostate cancers. The number of circulating CD57-positive cells increases in the blood of patients who have recently undergone organ or tissue transplantation, especially of the bone marrow, and of patients with HIV.

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