CLL cells from patients on ruxolitinib were exposed to higher TNFα and lower IL10 plasma levels and exhibited an activation phenotype consisting of increased expression of NFκB-regulated genes including IL10 and CD83 along with phosphorylated intermediates of NFκB-signaling pathways coupled with lower phospho-STAT proteins (Figure 1 and Supplementary Figure 1). Here, IL10 is linked to B-cell chronic lymphocytic leukemia.