We categorized the immunohistochemical CD133 values in three different ways (see also Materials and Methods): (i) CD133 negative (<1 %) versus CD133 positive; (ii) Low (>1 and <10 %) versus high (>10 and <50 %) CD133 expression; (iii) CD133 expression in <50 % of tumor cells versus CD133 expression in >50 % of tumor cells. The gene discussed is PROM1; the disease is neoplasm.