CD133+stem/progenitor cells, also referred to as tumor-initiating cells, CSCs, stem-like cells [9, 20, 23, 29, 30, 43-47], have been isolated in normal and neoplastic tissue including the human kidney and RCC [9-11, 27, 29, 45, 48, 49]. This evidence concerns the gene PROM1 and neoplasm.