Purity ~95% (SDS-PAGE). The B cell-activating factor from the TNF family (BAFF), is emerging as an important regulator of B cell and T cell responses. BAFF was originally identified as a factor responsible for B cell survival and maturation. BAFF binds to several receptors. These include transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), BAFF-R (BR3), and B cell maturation Ag (BCMA). BAFF-R appears to be particularly important for the regulation of B cell survival and maturation in the spleen, because A/WySnJ mice expressing a defective BAFF-R have disrupted B cell maturation, similar to that seen in BAFF-deficient mice. Source: Recombinant protein corresponding to human BAFF-R expressed in E. coli. Molecular Weight: ~9kD Biological Activity: The ED50 as determined by the dose-dependent stimulation of Raji cells was <0.5ng/mL. Endotoxin: <1EU/ug (LAL)