The tumor microenvironment has lately emerged as a major contributor to tumorigenesis, by providing either proliferative or inhibitory signals to the malignant cells.29 This is especially true for CRC, whose progression is substantially affected by cytokines and inflammatory mediators released in the tumor milieu.30,31 As an alarmin preferentially expressed in epithelial cells at barrier sites, and because of its role in intestinal disorders, IL-33 has recently gained particular attention for its contribution to CRC. Here, IL33 is linked to neoplasm.