An oncogenic function of epithelial IL-6-Stat3 signaling was identified in the azoxymethane–dextran sulfate salt (AOM-DSS) mouse model of colitis-associated CRC.25 In the sporadic ApcMin CRC model, Stat3 had a tumor-suppressive function in cancer cells and prevented epithelial-to-mesenchymal transition (EMT) and invasiveness.26 Similarly, a tumor-suppressive function of epithelial Stat1 was found in the AOM-DSS CRC model, but only in male mice.27 In ApcMin mice, epithelial Stat1 had an oncogenic function and promoted the formation of Ido1-expressing cancer cells that mediated immune escape.28 Here, IDO1 is linked to colorectal carcinoma.