title: Stem cells: an autonomous cell producing system.
abstract: Stem cells have been traditionally considered to be a reserve population, in which the primary control is the rate of differentiation. Alterations in proliferation rate are then considered to be the results of changes in the number of stem cells. This article suggests that perhaps the reverse is true, namely that the rate of stem cell production is primarily controlled, and not the number of stem cells.
mesh_terms: D002454:Cell Differentiation; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D008954:Models, Biological