(Cell 142, 309–319; July 23, 2010) In the original version of this paper, the authors neglected to acknowledge the contributions of Dr. Mathieu Ferron, who assayed osteocalcin levels in blinded samples (described in Figure 4) and assisted in performing the osteocalcin infusion studies (described in Figure 5). An edited version of the acknowledgments is included below, and the authors apologize for any inconvenience this may have caused. We are grateful for the assistance of the Small Animal Phenotyping Core and Metabolism Core Laboratory at the University of Alabama at Birmingham. We thank Dr. D. Accili for providing the tTR-IRKO mice and Dr. M. Bouxsein for assistance in analyzing the skeletal phenotype by micro-CT. We thank Dr. M. Ferron who provided osteocalcin measurements in serum and media samples and assisted in performing the osteocalcin infusion studies described in Figure 5. We also thank Drs. T. Nagy and T. Garvey for helpful suggestions during the completion of this work. Support was provided by a Merit Review Grant from the Veterans Administration (T.L.C.) and grants from the NIH (M.H., DK081472), the Baltimore Diabetes Research and Training Center (M.H., DK079637), and DFG (J.C.B., Br1492/7-1). T.L.C. is also the recipient of a Research Career Scientist Award from the Veterans Administration.