First, in the retrospective cohort of CRC patients, we showed herein that intracellular IL-18 detected by immunohistochemistry, i.e., mainly the proform, was maintained in tumor cells in the majority of CRCs compared to the paired normal colonic epithelial cells they derived from, although at variable levels in terms of number of positive cells within the tumor and staining intensity. Here, IL18 is linked to colorectal carcinoma.