Chronic lymphocytic leukaemia cell fate depends on microenvironment signals, which promote anti‐apoptotic and proliferative circuitry involving STAT and NFκB transcription factors.6, 7 Since these transcription factors are known PIM inducers,23 we hypothesized that expression of PIM kinases might be regulated by the interaction between CLL cells and their microenvironment. Here, PIM1 is linked to B-cell chronic lymphocytic leukemia.