BCR-signaling pathway showing kinase inhibitors, already approved or potentially useful in CLL, and their biological targets. BLNK, B-cell linker; Cdk, cyclin-dependent kinase; DAG, diacylglycerol; Lyn, member of the Src family of protein tyrosine kinases; NF-κB, nuclear factor κB; PIP2, phosphatidylinositol 4,5-bisphosphate; PIP3, phosphatidylinositol (3,4,5)-trisphosphate; PKC, protein kinase C; PLC, phospholipase C; mTOR, mammalian target of rapamycin.