PathScan^® RP Total B7-H4 Sandwich ELISA Kit #14520

B7 homolog 4 (B7-H4, VTCN1) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses (1-3). B7-H4 protein contains two extracellular Ig-like V-type domains, a transmembrane domain, and a short, two amino acid intracellular domain (3). The B7-H4 protein is shown to inhibit T cell activation, proliferation, and cytokine production (1,4,5). Although B7-H4 mRNA is widely expressed, B7-H4 protein is restricted to antigen presenting cells and B cells (1). The B7-H4 protein is also found in several tumor types, including ovarian cancer and breast cancer (6). Research studies indicate that B7-H4 protein is present on the surface of ovarian tumor cells, and that targeted inhibition of B7-H4 using recombinant antibodies restores T cell activation pathways. These studies suggest some potential therapeutic value in blocking B7-H4 function and restoring T cell function in cancer patients (7,8).