In proliferating-phase IH, the HemSC was identified as a rare CD133+ subset comprising approximately 1% of the tumor cell population, with vasculogenic potential (de novo vessel formation), clonogenic ability to self-renew, multipotential ability to give rise to several cellular lineages with distinct morphologies and gene expression profiles, and potential to regenerate GLUT1+ tumors containing the HemSC and the differentiated derivatives6, 10, 14, 16. This evidence concerns the gene PROM1 and neoplasm.