B-Cell Activating Factor (BAFF)

B-cell activating factor (BAFF) is the tumor necrosis factor ligand superfamily member 13B (TNFLSF13B), also known as B Lymphocyte Stimulator (BLyS) and TNF- and APOL-related leukocyte expressed ligand (TALL-1) and the Dendritic cell-derived TNF-like molecule (CD257 antigen; cluster of differentiation 257). BAFF is a 285-amino acid long peptide glycoprotein which undergoes glycosylation at residue 124. It is expressed as transmembrane protein on various cell types including monocytes, dendritic cells and bone marrow stromal cells. The transmembrane form can be cleaved from the membrane, generating a soluble protein fragment. BAFF is the natural ligand of three unusual tumor necrosis factor receptors named BAFF-R, TACI, and BCMA, all of which have differing binding affinities for it.