Nat. Med.; 10.1038/nm.4307; corrected online 11 April 2017

In the version of this article initially published, there were two typographical errors in the Abstract. The unnecessary 'h' in the line “Furthermore, h according to.....” has been deleted. The line “OSM is thus a potential biomarker of and therapeutic target for IBD,....” was changed to read “OSM is thus a potential biomarker and therapeutic target for IBD...”. These errors have been corrected in the HTML and PDF versions of the article. A coding error that inadvertently resulted in incorrect ordering of the authors in the HTML version was also corrected.