Association between B7-H1 expression and bladder cancer: a meta-analysis
B7 homolog 1 (B7-H1), which is also known as programmed death-L1, is an important member of the B7/CD28 costimulatory factor superfamily, which are emerging as important mediators of various host immune responses. B7-H1 is differentially expressed in various cell subsets and to different extents in human and murine cells. Human B7-H1 is constitutively expressed at low levels in dendritic cells and activated T cells (compared with high expression in activated murine T cells) and is highly expressed in monocytes and tumor cells.