The paramount relevance of BCR signaling to CLL homeostasis has prompted the development of novel inhibitors targeting BCR-related kinases, such as ibrutinib, a Bruton's tyrosine kinase (BTK) inhibitor with superior efficacy than several chemotherapy and chemoimmunotherapy treatments (9) [e.g., conventional therapy with bendamustine plus rituximab (12, 14)], or idelalisib, the first-in-class phosphatidylinositol 3-kinase delta (PI3Kδ) inhibitor for treatment of B-cell malignancies (15, 16). Here, BTK is linked to B-cell chronic lymphocytic leukemia.