Once again these results correlate with the exposure of DU 145 cells (lacking CD133) to anti‐CD133‐saporin, in which case, toxicity induced by either toxin alone or targeted was similar.52 Importantly, high proliferative capacity and tumour formation ability was confirmed with cells that highly express CD133 in vitro and in vivo; thus, targeted PCI could be in this case be a highly effective treatment against aggressive, and rapidly metastasising tumours. Here, PROM1 is linked to neoplasm.