The immune system protects the body from diseases and infections. In the case of autoimmune diseases, the immune system mistakenly attacks the healthy cells of the body. Autoimmune diseases can affect many parts of the body and more than 80 different forms of autoimmunity have been identified. The result of autoimmunity is the production of antibodies and specific cells directed against the patient's own tissues and organs and not just against "foreign" invaders such as microbes and viruses. Some examples of autoimmune diseases include type 1 diabetes, celiac disease, rheumatoid arthritis, systemic lupus erythematosus, Hashimoto's thyroiditis, multiple sclerosis, and more.