PROM1 and neoplasm: Moreover, Canis et al. [51] showed that stable transfection of CD133 in the human embryonic kidney 293 (HEK293) cell line induced tumor-initiating properties in these cells, and that HEK293 CD133high transfectants, when injected into SCID mice, generated tumors with at least a 1000-fold increased frequency as compared with CD133low cells.