Description: The 6C3 monoclonal antibody reacts with mouse BP-1, also known as Ly-51 and 6C3 antigen. BP-1 is a 140 kDa type II transmembrane protein that is present on the surface as a disulfide-linked homodimer. This molecule is an enzyme with aminopeptidase A (APA) activity and is expressed by bone marrow stromal cells, thymic cortical epithelial cells and at early stages of mouse B cell development, on pre-B cells. The low level of BP-1 expression on pre-B cells can be upregulated in the presence of IL-7.