IL1RL1 and colorectal carcinoma: IL-33 expression has been shown to become upregulated upon neoplastic transformation of human and murine colonic tissues and to promote intestinal tumorigenesis.15,16 To address the role of the IL-33/ST2 axis on immune cells in CRC, we treated C57BL/6 and BALB/c mice with azoxymethane (AOM)/dextran sulfate sodium (DSS).