CD75 is encoded by this gene is a type II membrane protein that catalyzes the transfer of sialic acid from CMP sialic acid to galactose-containing substrates. The encoded protein, which is normally found in the Golgi apparatus but which can be proteolytically processed to a soluble form, is involved in the generation of the cell surface carbohydrate determinants and differentiation antigens HB6, CDw75, and CD76. This protein is a member of glycosyltransferase family 29. Three transcript variants encoding two different isoforms have been found for this gene. This antibody recognizes the CD75 cell surface antigen, an alpha 2,6 sialyated carbohydrate epitope expressed by mature B cells, especially germinal centre B cells, red blood cells and some epithelial cells.