Unsupervised hierarchical cluster analysis of IL10- and TGFβ1-expressing B cells from a first cohort of 28 CLL patients (UPN; Table 1 and Supplementary Table 1) distinguished 2 clusters (Cluster 1 n = 17 & Cluster 2 n = 11) with a higher proportion of cells expressing both cytokines in group 2 (Fig. 4D). Here, IL10 is linked to B-cell chronic lymphocytic leukemia.