PROM1 and glioblastoma: In addition to the cancer stem cells, CD133 is also expressed in hematopoietic stem cells, endothelial progenitor cells, glioblastoma, neuronal and glial stem cells, pediatric brain tumors, adult kidney, mammary glands, trachea, salivary glands, uterus, placenta, digestive system, testes, and other cell types.