Mouse secreted B7-1-Fc fusion protein, also known as CD80, with C-terminal Avi-tag fused at the C-terminus to the Fc region of Human IgG1. GenBank Accession No. NM_009855, a.a 38-246 expressed in a HEK293 cell expression system. MW = 52 kDa. This protein runs at a higher M.W. by SDS-PAGE due to glycosylation.