AUTHOR=Tobias Jon TITLE=Grand Challenges in Bone Endocrinology JOURNAL=Frontiers in Endocrinology VOLUME=1 YEAR=2010 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2010.00008 DOI=10.3389/fendo.2010.00008 ISSN=1664-2392