Purity: > 90% by SDS - PAGE Format: Liquid. In Phosphate Buffered Saline (pH 7.4) containing 10% glycerol.. MS4A1, also known as B-lymphocyte antigen CD20, is an activated-glycosylated phosphoprotein expressed on the surface of all B-cells beginning at the pro-B phase and progressively increasing in concentration until maturity. It is to enable optimal B-cell immune response, specifically against T-independent antigens. It is suspected that it acts as a calcium channel in the cell membrane. It plays a role in the microenvironmental interactions of B cells. This structurally unique phosphoprotein plays a role in the regulation of human B cell proliferation and differentiation. It was strongly phosphorylated on resting B cells after CDw40 stimulation, suggesting that it may be functionally regulated by a protein kinase. Recombinant human MS4A1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.