STAT1 and B-cell chronic lymphocytic leukemia: Because the differentiation and expansion of Th17 cells are dependent upon signals supplied by the cytokines IL-6 and IL-1β, among others [36–38], we next analyzed signaling downstream of IL-6 (measured via p-STAT1/3/4) and IL-1β (measured via pNFkBp105) in CD4+CD3+ and CD4−CD3+ T cells from CLL patients and healthy controls.