CD4 and colorectal carcinoma: In contrast to IL-1, a recent study in CRC reported that the IL-33/ST2 axis regulates T-cell plasticity, by stabilizing the phenotype of IL-17negFOXP3+ Tregs and potentially promoting the conversion of IL-17-producing CD4+ T cells into these IL-17neg (RORγtneg) FOXP3+ Tregs [294].