title: Pre-progenitor cells: a proposed new category of hematopoietic precursor cells.
abstract: Hematopoietic precursor cells capable of forming blast colonies in vitro appear to be a distinct transit population between stem cells and lineage-committed progenitor cells because the cells in such blast colonies are mainly lineage-committed progenitor cells. It is proposed that blast colony-forming cells be termed pre-progenitor cells (PPC) to encourage efforts to establish their biology and potential for initiating some types of leukemic populations more clearly.
authors.forename: D
authors.initials: D
authors.lastname: Metcalf
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D003114:Colony-Forming Units Assay; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000145:classification* / Q000166:cytology; D006801:Humans; D007938:Leukemia / Q000473:pathology; D008954:Models, Biological