The niche for hematopoietic stem cell expansion: a collaboration network

Transplantation of hematopoietic stem/progenitor cells(HSPC)has become one of the most effective treatments for several hematological malignancies,cancers and genetic immune disorders.However,the lack of histocompatible donor sources and the number of stem cells suitable for engraftment are major constraints in the clinic,and these constraints greatly hamper the use of stem cell therapy.In humans,fetal liver and bone marrow are the two major locations of hematopoiesis before and after birth,respectively.Thus,understanding the specialized stem cell microenvironment supporting the self-renewal and expansion of HSPC in fetal liver and bone marrow is not only essential for extending the current knowledge of stem cell biology but is also beneficial to adult regenerative medicine in the clinic.