An example of the how advances in biotechnology are allowing medicine to move closer towards intervening in first causes at the biochemical level: researchers "have developed a new approach for identifying the 'self' proteins targeted in autoimmune diseases such as multiple sclerosis, diabetes and rheumatoid arthritis. ... errant immune responses which mistakenly target the body's own proteins rather than foreign invaders can now be examined in molecular detail. Further research could lead to new insights into the exact causes of these debilitating autoimmune disorders. ... The immune system, the body's main line of defense against disease, has a critical responsibility to distinguish self-derived proteins from those of invaders like viruses and bacteria. Autoimmune diseases arise when a person's immune system fails to make that critical distinction and mistakenly attacks a normal tissue, such as nerve, joint, or insulin-producing pancreatic cells. ... Knowledge of the self-antigens involved in autoimmune processes is important not only for understanding disease etiology, but also for developing diagnostic tests. In addition, physicians may someday use antigen-specific therapies to destroy or disable auto-reactive immune cells. ... But looking through the haystack of cellular complexity for those single-needle self-antigens targeted by the immune system has proved daunting, to say the least. Ideally, scientists would be to develop some kind of biological magnet that could pull these fine needles out of the mass. In this report, the researchers describe an approach which does just that."