This product detects CD274, also known as B7-H1 and PD-1L, a cell surface glycoprotein which is a member of the B7 family of co-stimulatory molecules. CD274 is expressed constitutively on macrophages and dendritic cells, and is induced on activated T-cells, B-cells, endothelial cells and epithelial cells in response to Interferons alpha, beta and gamma.

CD274 is reported to possess dual functions; inhibition of activated effector T cells and co-stimulation of naive T cells. CD274 inhibits proliferation of activated T cells via ligation to the co-inhibitory molecule CD279 (programmed death-1; PD-1) leading to the secretion of the regulatory cytokine interleukin-10. CD274 has also been shown to co-stimulate early T cell priming and differentiation.

Deregulated CD274 function has been reported in chronic viral and intracellular bacterial infection, as well as in many autoimmune diseases and cancers.