title: Progress and obstacles towards generating hematopoietic stem cells from pluripotent stem cells.
abstract: OBJECTIVE
  Human pluripotent stem cells (PSCs) have the potential to provide an inexhaustible source of hematopoietic stem cells (HSCs) that could be used in disease modeling and in clinical applications such as transplantation. Although the goal of deriving definitive HSCs from PSCs has not been achieved, recent studies indicate that progress is being made. This review will provide information on the current status of deriving HSCs from PSCs, and will highlight existing challenges and obstacles.
  
  
  RESULTS
  Recent strides in HSC generation from PSCs has included derivation of developmental intermediates, identification of transcription factors and small molecules that support hematopoietic derivation, and the development of strategies to recapitulate niche-like conditions.
  
  
  CONCLUSIONS
  Despite considerable progress in defining the molecular events driving derivation of hematopoietic progenitor cells from PSCs, the generation of robust transplantable HSCs from PSCs remains elusive. We propose that this goal can be facilitated by better understanding of the regulatory pathways governing HSC identity, development of HSC supportive conditions, and examining the marrow homing properties of PSC-derived HSCs.
authors.affiliation: aDepartment of Stem Cell and Regenerative Biology, Harvard University, Cambridge bProgram in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital cDepartment of Dermatology, and Program of Excellence in Glycosciences, Brigham & Women's Hospital, Harvard Medical School dDivision of Hematology, Department of Medicine, Brigham & Women's Hospital eDepartment of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston fHarvard Stem Cell Institute, Cambridge, Massachusetts, USA *Jungmin Lee and Brad Dykstra contributed equally to the writing of this manuscript.
authors.forename: Jungmin
authors.initials: J
authors.lastname: Lee
authors.forename: Brad
authors.initials: B
authors.lastname: Dykstra
authors.forename: Robert
authors.initials: R
authors.lastname: Sackstein
authors.forename: Derrick J
authors.initials: DJ
authors.lastname: Rossi
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D019070:Cell Lineage / Q000276:immunology; D002465:Cell Movement / Q000187:drug effects; D064987:Cell- and Tissue-Based Therapy / Q000379:methods* / Q000639:trends; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D054852:Small Molecule Libraries / Q000494:pharmacology*; D055153:Stem Cell Niche / Q000187:drug effects; D014157:Transcription Factors / Q000494:pharmacology*
chemical_list: D054852:Small Molecule Libraries; D014157:Transcription Factors