To date, since the publication of these encouraging pioneer studies, more than 30 different autoimmune and inflammatory diseases have been treated with low-dose IL-2 therapy in pilot studies, uncontrolled clinical trials and lastly also randomized clinical trials, including SLE, T1D, rheumatoid arthritis, ankylosing spondylitis, psoriasis, Behcet’s disease, granulomatosis with polyangiitis, Takayasu’s disease, Crohn’s disease, ulcerative colitis, autoimmune hepatitis, sclerosing cholangitis, Sjogren ́s syndrome, alopecia areata and inflammatory myopathies (see Table 1 for details) (16). This evidence concerns the gene IL2 and Crohn disease.