Although BTK is central to BCR signaling and an important target in other B-cell malignancies such as chronic lymphocytic leukemia (CLL), mantle cell lymphoma or WM, results of the phase 2 DAWN study (37) (ibrutinib in R/R FL) were disappointing, with an ORR of only 20%. This evidence concerns the gene BCR and B-cell chronic lymphocytic leukemia.