The four hemophiliacs must constantly tap into that supply. Two contract AIDS and are dead within three years. The third has tested HIV-positive; it is only a matter of time before the patient exhibits clinical symptoms, suffers, and dies. The fourth, age thirty, himself the father of three, has refused to be tested, but he knows that the chances are overwhelming that he too is a carrier, and that he will shortly leave his wife a widow and his children fatherless. He has almost no insurance, and