Hematopoietic stem cell expansion and generation: The ways to make a breakthrough

Hematopoietic stem cell transplantation (HSCT) is the first field where human stem celltherapy was successful. Flooding interest on human stem cell therapy to cure previouslyincurable diseases is largely indebted to HSCT success. Allogeneic HSCT has been an importantmodality to cure various diseases including hematologic malignancies, variousnon-malignant hematologic diseases, primary immunodeficiency diseases, and inbornerrors of metabolism, while autologous HSCT is generally performed to rescue bone marrowaplasia following high-dose chemotherapy for solid tumors or multiple myeloma.Recently, HSCs are also spotlighted in the field of regenerative medicine for the ameliorationof symptoms caused by neurodegenerative diseases, heart diseases, and others.Although the demand for HSCs has been growing, their supply often fails to meet thedemand of the patients needing transplant due to a lack of histocompatible donors ora limited cell number. This review focuses on the generation and large-scale expansionof HSCs, which might overcome current limitations in the application of HSCs for clinicaluse. Furthermore, current proof of concept to replenish hematological homeostasis fromnon-hematological origin will be covered.