CD267, also known as TACI (transmembrane activator and calcium modulator and cyclophilin ligand interactor) or TNFRSF13B, is a member of the tumor necrosis factor (TNF) receptor family that serves as a receptor for B-cell activating factor of the TNF family (BAFF/CD257) and as a proliferation-inducing ligand (APRIL/CD256). BAFF and APRIL bind both TACI and BCMA (B cell maturation Ag/CD269), with BAFF additionally and exclusivel y binding the BAFF receptor (BAFF-R/CD268) while APRIL can also bind to heparin sulfate proteoglycan s (HSPG). TACI is expressed on B cells and activated T cells. BC MA is exclusively expressed on B cells, whereas BAFF-R is expressed mainly on B cells but also on T cells. It is reported that mutations of CD267/TACI are showed in patients with IgA deficiency and common variable immunodeficiency (CVID). Sakurai et al ., reported that TACI positively regulated APRIL-induced IgA production in collaboration with HSPG and TACI negatively regulated BAFF-induced B-cell proliferation and production of IgA and IgG.Synonyms: TNFRSF13B, Transmembrane activator and CAML interactor, Tumor necrosis factor receptor superfamily member 13B