CD20 Antibody

CD20 is a non-Ig differentiation antigen of B-cells and its expression is restricted to normal and neoplastic B-cells, being absent from all other leukocytes and tissues. It is expressed by pre B-cells and persists during all stages of maturation but is lost upon terminal differentiation into plasma cells. The protein passes through the membrane 4 times with both ends in cytoplasm and exposes one short and one longer loop to the external environment. It acts as a calcium channel involved in B-cell activation and cell cycle progression.