Lastly, a significant interaction effect (p = 0.0287) was observed between the addition of CLL B cells and the particular Th17-promoting cytokine(s) added indicating that the stimulatory effect of CLL B cells on IL-17F production by CD4+ T cells is dependent upon the specific cytokine cocktail used to trigger Th17 differentiation. Here, CD4 is linked to B-cell chronic lymphocytic leukemia.