Because IL-7 activates adaptive immunity, IL-7 is contraindicated in patients with autoimmune diseases including for example, Crohn’s disease, lupus, myasthenia gravis, rheumatoid arthritis, etc. IL-7 is also contraindicated in patients who have T cell malignancies because IL-7 therapy could cause the malignant T cells to undergo more rapid proliferation. Here, IL7 is linked to Crohn disease.