Therefore, we propose that the IL-33/ST2 axis regulates T cell plasticity in CRC tissue, by stabilizing the phenotype of IL-17-negative FOXP3+ Tregs and potentially promoting the conversion of IL-17-producing CD4+ T cell types to these IL-17-negative (RORγt−) FOXP3+ Tregs. This evidence concerns the gene IL1RL1 and colorectal carcinoma.