Ibrutinib affects miR-181a and miR-181b expression in vivo. (A) Evaluation by reverse transcription quantitative polymerase chain reaction (RT-qPCR) of miR-181a and miR-181b relative expression in purified primary CLL cells collected at the first time point (FTP) and at the last time point (LTP) of ibrutinib treatment follow-up. RNU44 was used as an internal control. The expression of miRNAs was normalized to the level of the basal time point at each time point. The Wilcoxon matched-pairs test was used for statistical significance. (B) Evaluation by RT-qPCR of miR-181a and miR-181b expression (left y-axis) in purified primary CLL cells collected during the follow-up of ibrutinib treatment (x-axis; days); RNU44 was used as an internal control. The expression of miRNAs was normalized to the level of the basal time point at each time point. WBC count at each time point was reported on the right y-axis. Black arrows indicate when the WBC count of patients decreased by >50% from baseline, or reached physiologic values at the last time point (WBC with properties). Conversely, gray arrows represent time points where the WBC count of patients decreased by <50% from baseline or remained unchanged (WBC without properties). (C) Graphs illustrate the corresponding expression levels of miR-181a and miR-181b in patients with CLL, as indicated. Wilcoxon matched-pairs test was used for statistical significance; ∗P<.05.