For example, lower activity of DPPIV in serum is found in patients with diabetes mellitus, hypertension associated with angioedema induced by angiotensin-converting enzyme treatment, in disorders such as anxiety and depression, in patients with autoimmune diseases and different immune-mediated disorders, including rheumatoid arthritis, systemic lupus erythematosus and inflammatory bowel disease. The gene discussed is ACE; the disease is systemic lupus erythematosus.