If the treatment works, do we need to know why?: the promise of immunotherapy for experimental medicine

There has been much fanfare, and rightly so, heralding a revolution in the treatment of autoimmune disease using biologic agents—antibodies or other molecules that specifically target known mediators of disease. But not all patients respond to even the most successful biologic agent, which may provide clues about alternate disease mechanisms. Studies aimed at understanding the mechanism of action of biologic agents will yield significant benefits for experimental medicine.