PROM1 and glioblastoma: To show that transduction is mediated by this interaction, we treated our GBM cells with increasing amounts of an antibody recognizing the same epitope as the CD133-LV viral envelope protein (293C3, blocking antibody), or with an antibody that recognizes a different epitope on CD133 (AC133, non-blocking antibody) and measured transduction efficiency with CD133-LV by flow cytometry (Fig. 2C).