STAT3 and B-cell chronic lymphocytic leukemia: Phosphorylation at S727 is crucial to maximise STAT3 transcriptional activity, which promotes tumorigenesis in prostate cancer19 and chronic lymphocytic leukaemia.20 Because NF-κB is one of the downstream effectors of STAT3 and AKT,21 we additionally detected siPDK4-mediated reduction of p-p65 S536 protein expression (p-RelA) (Fig. 6b).