Correction for Roper et al., Defective cerebellar response to mitogenic Hedgehog signaling in Down’s syndrome mice

medical sciences. For the article “ Defective cerebellar response to mitogenic Hedgehog signaling in Down’s syndrome mice,” by Randall J. Roper, Laura L. Baxter, Nidhi G. Saran, Donna K. Klinedinst, Philip A. Beachy, and Roger H. Reeves, which appeared in issue 5, January 31, 2006, of Proc. Natl. Acad. Sci. USA (103, 1452–1456; first published January 23, 2006; 10.1073/pnas.0510750103), it should be noted that all instances of “Down syndrome” incorrectly appeared as “Down’s syndrome,” due to an editorial error that occurred after author approval of the proofs.