To obtain putative stem cells for identification of novel CSC biomarkers, CD133+ cancer cells were isolated from various human tumor cell lines, including MDA-MB-231 Triple-negative breast cancer (TNBC), H460 and A549 (lung cancer), OVCAR-5 and HEY (ovarian cancer), from subcutaneous human lung tumor xenografts established in immunodeficient mice and from surgically resected primary breast tumor tissues from six patients. This evidence concerns the gene PROM1 and ovarian cancer.