While IL-15koRAG2ko mice had to be killed due to the rapid body weight loss within 4 weeks post transfer, the remaining groups of hosts did not show remarkable pathological changes up to 9 weeks post transfer (Supplementary Fig. 4b,c), demonstrating that the severe colitis induced by T cells in absence of IL-15 was not observed in the absence of IL-6. This evidence concerns the gene IL6 and colitis.