[Molecular and biological features of human CD34+ Hematopoietic stem/progenitor cells]

It is generally held that control of viability, proliferation, differentiation, maturation and programmed cell death events in hematopoietic stem/progenitor cells existing in a hierarchical fashion in vivo is a successively developmental process. The CD34+ antigen preferentialy expressed on hematopoietic stem/progenitor cells has so far been recognized as one of the earliest known antigens. Many advances on molecular structure of CD34 antigen would help us to understand deeply a lot of important questions regarding CD34+ hematopoietic stem/progenitor cells. These questions are, for instances, functional subclass, expression range and other biological properties including cell cycle state, fluorescent light scatter, ect. All of these studies would renew and consummate the modern concept of hematopoietic stem cells and the fundamental model of hematopoiesis and its regulation.