Autoimmune diseases, inflammatory diseases, allergic diseases, the therapeutic agents and conditions associated with organ transplantation prophylactic
A major object of the present invention is to provide a novel therapeutic or prophylactic agent for at least one disease or symptom selected from the group consisting of autoimmune diseases, inflammatory diseases, allergic diseases, and symptoms accompanying organ transplants； the therapeutic or prophylactic agent artificially controls the activity of IL-6 amplifier, thus controlling immune reactions in living organisms. Another object of the present invention is to provide an immunosuppressant, an inflammatory cytokine production inhibitor, and an IL-6 amplifier inhibitor. The compound that inhibits expression of the function of a protein belonging to ErbB1 pathway provided as means for achieving the object is capable of suppressing the activity of IL-6 amplifier, thereby reducing production of inflammatory cytokine such as IL-6. Therefore, the compound that inhibits the function of a protein belonging to ErbB1 pathway can be used as an active ingredient of the therapeutic agent or the prophylactic agent for at least one disease or symptom selected from the group consisting of autoimmune diseases, inflammatory diseases, allergic diseases, and symptoms accompanying organ transplants.
