In order to test this hypothesis, we profiled the microbiota of stool samples collected from mice suffering from colitis alone (eg, Il10−/− mice and Rag1−/− mice on colitis induction via transfer of CD45Rbhigh cells) and with concomitant sclerosing cholangitis (eg, Il10−/−Mdr2−/− mice and Rag1−/−Mdr2−/− mice on colitis induction via transfer of CD45Rbhigh cells) (online supplemental figure S5). This evidence concerns the gene RAG1 and colitis.