UN-CORRECTED PROOF * IMAGINE* You have a really close friend, one you see everyday, one with whom you have exchanged confidences and shared experiences, and had so many fun times together. Imagine the worst possible disease, and then think how you would feel if you found out your friend had it. Imagine watching your buddy as he fought such a horrible disease, seeing him succumb to that disease---a person you love, a friend who has been such an important...