STAT3 and B-cell chronic lymphocytic leukemia: To determine how these cytokines affected resiquimod-signaling in CLL cells in vitro, purified CLL cells were cultured for 1-2 days in pre-optimized concentrations of IL-10, IL-6, IL-4, IFN-β or a mixture of the chemokines CXCL8, CXCL10, CCL2, CLL3, and CCL5 some of which can also activate STAT3 (40, 41).