CD133 is a stemness marker that is related to increased tumor-initiating ability, tumor progression, and cancer recurrence in numerous types of cancer (43); thus, the CD133 expression cell subset is generally referred to as a colony-forming cell that possesses seed-cell property and provides an explanation of self-renewal and metastatic potential of cancer cells (31, 44, 45). The gene discussed is PROM1; the disease is cancer.