CXCR4 and B-cell chronic lymphocytic leukemia: These two genes were selected after an initial screening for genes responding to anti‐IgM stimulation in primary CLL, and for which the response was repressed by addition of ibrutinib looking at EGR1, DUSP2, MYC, DUSP4, CCND2, BCL2A1, PRDX1, NCL, CDC25B, TLR10, PIM1, CXCR4, CXCR5, CCR6 and CCR7. From these genes, only the first 5 were convincingly stimulated and repressed without or with ibrutinib, respectively.