Fig. 1

Schematic of the CD133 topology and putative epitopes of commercially available CD133 antibodies. The five transmembrane glycoprotein contains two large extracellular loops (EC2 and EC3), which comprise a total of nine N-linked glycan residues. The commonly used CD133/1 and CD133/2 epitopes are located on the EC3 region of CD133 and have the potential for epitope masking or antibody inaccessibility due to changes in glycosylation patterns