Cells expressing the CD133+ (AC133, Prominin-1) marker are generally known as primitive hematopoietic stem and progenitor cells (HSC and HPC). Capable of a high level of proliferation and a wide range of differentiation, transplantation of CD133+ cell lines have been shown to not only induce multilineage human hematopoiesis through the CD34+ lineage, but also induce regeneration of cell lines in vitro. CD133+ stem cells are isolated using positive immunomagnetic cell separation procedures from a mobilized leukapheresis collection.