Seven days before the cells are re-infused, the patient is admitted to the hospital and a catheter (small tube) is placed in a large vein in the chest or neck. Two drugs, cyclophosphamide and fludarabine, are given through the tube. These drugs suppress the immune system so that it will not interfere with the work of the reinfused lymphocytes. The lymphocytes are then injected through the catheter over a 30-minute period. After the infusion, patients who receive IL-2 will be given the drug in a high dose over a 15-minute period every eight hours for up to five days. Patients whose condition does not permit high-dose IL-2, such as those with a heart condition or lung problem, may receive a low-dose regimen, with the drug given as a shot under the skin of the thigh or abdomen for five days followed by a 2-day break, continuing for a total of six weeks. These patients receive a higher dose the first week and then half that dose the next five weeks.