Taken together with the results of previous studies, our current findings suggest that increased expression of ST2 in the tumor microenvironment, as a primary functional receptor for IL-33, was started from the adenoma stage and persisted to the CRC stage, which suggest that ST2 could be the functional receptor for IL-33 in promoting the development of adenoma/CRC (Fig. 7). Here, IL1RL1 is linked to adenoma.