Due to the data, thousands of patients suffering from a variety of autoimmune diseases were treated with recombinant human IL-10 (rHuIL-10) in clinical trials. Contrary to expectations, rHuIL-10 treatment did not significantly impact disease in patients with Crohn's disease. or rheumatoid arthritis. rHuIL-10 treatment initially exhibited promising clinical data in psoriasis. but failed to achieve clinical significance in a randomized, double blind, placebo controlled Phase II trial. Further investigation of rHuIL-10's effects in humans suggests that rather than inhibiting inflammation, rHuIL-10 is capable of exerting pro-inflammatory effects.