This suggests that the balance of cytokines secreted by CLL Th17 cells differentiated within the CLL cellular microenvironment (mimicked in our PBMC cultures) may differ from that observed in Th17 cells differentiated within a “non-CLL” cellular microenvironment (IL-17F higher relative to IL-17A in Th17 cells differentiated within CLL milieu). This evidence concerns the gene IL17A and B-cell chronic lymphocytic leukemia.