In one study, 8 patients with relapsed ALL or CLL were treated with healthy donor allogeneic T-cells that were first enriched for virus-specific lymphocytes (cytomegalovirus (CMV), EBV, or adenovirus) prior to their transduction with a 2nd generation anti-CD19 CAR containing the CD28 costimulatory domain[138]. Here, CD28 is linked to B-cell chronic lymphocytic leukemia.