AUTHOR=Asakura Atsushi TITLE=Grand challenges in the field of stem cell research JOURNAL=Frontiers in Cell and Developmental Biology VOLUME=2 YEAR=2014 URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2014.00002 DOI=10.3389/fcell.2014.00002 ISSN=2296-634X