The rat monoclonal antibody 1A1 recognizes an extracellular epitope of CD267 / TACI, a 32 kDa type III transmembrane protein expressed by B cells and possibly by some activated T cells.
TNF receptor superfamily member 13B,CD267 / TACI (transmembrane activator calcium modulator and cyclophilin ligand interactor), a TNFR superfamily transmembrane protein, is expressed on B cells (predominantly on CD27+ memory cells), multiple myeloma cells and B cell chronic lymphocytic leukemia (B-CLL). Its triggering leads to activation of the transcription factors NFAT, AP1, and NF-kappa-B. It plays a crucial role in humoral immunity. Mutations in CD267 are associated with common variable immunodeficiency and IgA deficiency.,RYZN, TACI, CVID2, IGAD2, TNFRSF14B