Cluster of Differentiation 7 （CD7） is an antigen expressed in immature and mature T-lymphocytes, thymocytes, peripheral blood T-cells, natural killer cells, myeloid precursors, fetal liver and bone marrow, a small subpopulation of normal B-cells, and malignant B-cells. The antigen belongs to the immunoglobulin gene superfamily, and plays an important role in T-cell interactions and T-cell/B-cell interactions during early lymphoid development. CD7 is indicated as a marker for acute myelogenous leukemia and chronic myelogenous leukemia, and for neoplastic proliferations such as T-cell acute lymphoblastic leukemia/lymphoma. Anti-CD7, when used in adjunct with Anti-CD4, is useful for differentiating mycosis fungoides or Sezary syndrome （both cutaneous T-cell lymphomas） from benign dermatoses.
