Nevertheless, Tregs have a low activation threshold for IL-2, and the number and function of Tregs are dysregulated in most autoimmune diseases, such as type 1 diabetes, multiple sclerosis (MS), systemic lupus erythematosus (SLE), RA, inflammatory bowel disease, and psoriasis, making low-dose IL-2 a new therapeutic candidate for many autoimmune diseases with low toxic effects (84–86). Here, IL2 is linked to autoimmune disease.