Major changes in the expression of the BCL2 family members, have also been observed on protein level when CLL cells were cultured (7 days, n = 3) on plastic or HS5-CD40L-IL4-IL21 cells, including a ~80% repression of BCL2 (P = 0.007; Supplementary Fig. S2Eii). Here, IL4 is linked to B-cell chronic lymphocytic leukemia.