CD20 is a transmembrane phosphoprotein that functions as a calcium channel and participates in B cell activation, proliferation and differentiation. Expression is found on normal and malignant B cells, but not on plasma cells.
Antibody CD20 is a major marker for B cells and B cell derived neoplasms. CD20 may be helpful in detection of different B cell lymphoma, including lymphoblastic lymphoma/leukemia and diffuse large B cell lymphoma, as well as Reed-Sternberg cells in Hodgkin lymphoma.

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