IL15 and B-cell chronic lymphocytic leukemia: Although the effect under stimulation with IL-7/IL-15 was marked, stimulation with IL-2 also led to a higher proliferation rate of CD4+ and CD8+ CARTN cells from HDs in comparison to untreated CLL patients (day 20: CD4 + CARTN: 10-fold expansion; CD8+ CARTN: 36-fold expansion).