BCR and B-cell chronic lymphocytic leukemia: At present, CLL is treated with a fludarabine-cyclophosphamide-rituximab (FCR) combination and signaling inhibitors that target B-cell receptor (BCR)-associated kinases (i.e., Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib and acalabrutinib) or the antagonist of the B-cell lymphoma-2 (Bcl-2) anti-apoptotic protein (venetoclax) [40].