IL2 and B-cell chronic lymphocytic leukemia: With CpG and IL2 stimulation as backbone, given the well known proliferative effect on CLL leukemic cells [14], we found that the addition of NE, from HD or CLL patients decreased apoptosis (median % of apoptotic cells without NE vs NE from HD vs NE from CLL: 28 ± 27 vs 19 ± 23 vs 5 ± 17; p < 0.001), while the addition of the stroma cell line HS5 abrogated the positive effect of the NE resulting in similar protection from apoptosis in all 3 conditions (35%) (Figure 1A).