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. The gene discussed is PROM1; the disease is cancer.