There are studies and case reports in the literature describing patients treated with IL-2 or interferon who were subsequently diagnosed with new cases of autoimmune conditions including diabetes mellitus and thyroid disease as well as a report of 2 patients with exacerbations of their underlying Crohn disease.27, , -30 While there was an association noted in some of these patients, development of autoimmune disorders was not consistently correlated with therapeutic response. Here, IL2 is linked to Autoimmunity.