Stromal co‐culture of primary CLL cells resulted in up‐regulation of MCL1, BCL2 and BCLxL, with concomitant decreased expression of NOXA, BAX and PUMA (in at least two of the three samples analysed), compared to cells cultured in medium alone (Figure 4A). This evidence concerns the gene BCL2L1 and B-cell chronic lymphocytic leukemia.