BTK and B-cell chronic lymphocytic leukemia: The prevalence of CLL increases with age, and its clinical profile ranges from CLLs that may not require treatment to others that progress aggressively.1 In addition to conventional immunochemotherapies (such as fludarabine‐cyclophosphamide‐rituximab [FCR] and bendamustine‐rituximab [BR]), a number of novel drugs have significantly modified the treatment strategies in this disease; they include kinase inhibitors (ibrutinib and idelalisib, targeting Bruton's tyrosine kinase and phosphatidyl‐inositol 3‐kinase, respectively), and an antagonist of the antiapoptotic Bcl‐2 protein (venetoclax).2