We recently showed that Tyk2 mediates protective IL22 signaling in gut epithelial cells during DSS-induced acute colitis.48 We did not observe increased lethality of Tyk2Δ/Δ, Tyk2ΔHem or Tyk2ΔIEC mice during DSS-induced induction of chronic colitis in the AOM-DSS protocol. This evidence concerns the gene TYK2 and Chronic colitis.