This antibody reacts with the CD71-antigen, which is expressed on is expressed on proliferating cells, reticulocytes, and erythroid precursors, expression is very low on resting leukocytes, it is a 95 kD type II heterodimeric transmembrane glycoprotein also known as T9 and transferrin receptor. CD71 plays a role in the control of cellular proliferation by facilitating the uptake of iron via ferrotransferrin binding and the recycling of apotransferrin to the cell surface.