该基因编码一种属于b7共刺激蛋白家族的蛋白质。这个家族的蛋白质存在于抗原提呈细胞的表面，并与t细胞表面受体结合的配体相互作用。研究表明，高水平的编码蛋白与肿瘤的进展有关。这个基因的一个假基因位于20号染色体上。已发现该基因编码不同亚型的多个转录变体。[由RefSeq提供，2011年12月]
This gene encodes a protein belonging to the B7 costimulatory protein family. Proteins in this family are present on the surface of antigen-presenting cells and interact with ligand bound to receptors on the surface of T cells. Studies have shown that high levels of the encoded protein has been correlated with tumor progression. A pseudogene of this gene is located on chromosome 20. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Dec 2011]