PROM1 and brain neoplasm: Human-brain tumor-propagating cells (TPCs) [17], [18] express CD133 (CD133+) and are also CD15+ (also known as SSEA-1 or LeX), and they resemble neural progenitors, as they show clonogenic and multilineage differentiation capacity, and the ability to initiate tumors following orthotopic xenograft transplantation [19].