Description: The AISB12 monoclonal antibody reacts with mouse CD20. CD20 is a B cell-specific 32kDa membrane protein involved in intracellular calcium regulation. CD20 expression begins after the induction of CD19 during development, and is coexpressed with IgM during the pre-B to immature B cell transition in bone marrow. Expression then increases during maturation with almost all mature cells expressing some level of CD20. The human CD20 antigen has proven to be an effective immunotherapeutic target in B cell lymphoma and several autoimmune diseases including rheumatoid arthritis and type I diabetes. CD20 consists of 4 transmembrane domains and a 44 amino acid extracellular loop domain where AISB12 binds.