CD19 and B-cell chronic lymphocytic leukemia: To better clarify the role of IL-10 in mediating CLL survival, we then cultured CD19+ CLL cells stimulated with IL-10 in a dose escalation experiment (from 0.1 ng/ml to 100 ng/ml) and we found a moderate protection from apoptosis at different doses (n=4, Supplementary Figure S4).