Mouse Anti-Human CD257 Antibody (S-3021)

CD257, encoded by TNFSF13B and also known as BLyS or BAFF, is a 285-aa type-II transmembrane glycoprotein of the TNF ligand superfamily produced by monocytes, dendritic cells, macrophages and activated T cells that can be cleaved to a soluble homotrimeric cytokine which, via engagement of three receptors—BAFF-R, TACI and BCMA—delivers survival and maturation signals to B cells, orchestrates T-cell co-stimulation, and drives class-switching and antibody production through NF-κB and PI3K/AKT pathways, while excess CD257 triggers B-cell hyperplasia and autoantibody formation, linking its overexpression to systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis and multiple myeloma, and making CD257 antagonism (e.g., belimumab) a validated therapeutic strategy.