[Hematopoietic Stem Cells or Hematopoietic Progenitor Cells Maintain the Steady-State Hematopoiesis? -Editorial].

Current dogma suggests that hematopoietic stem cells (HSC) reside in the top of the hematopoietic hierarchy, which can provide all kinds of mature blood cells constantly through self-renewal and multilineage differentiation potential. HSC has been regarded as the main cell population that maintains the stable hematopoiesis and several differentiation and development patterns of HSC have been summarized based on transplantation results. However, in deed the transplantation experiment is based on an extremely situation of stress which could not really reflect the function of HSC in normal homeostatic condition. Recent studies show that hematopoietic progenitor cells (HPC) play the most important role in hematopoiesis based on different experimental strategies. This article focuses on the controversial subject of the function of HSC and HPC under homostasis.