Since the introduction of ibrutinib for CLL treatment, despite the durable clinical responses in the majority of patients, events of progression have started to be described, mainly because of the acquisition of BTK or PLCγ2 mutations (Woyach et al., 2014a; Liu et al., 2015; Ahn et al., 2017). This evidence concerns the gene BTK and B-cell chronic lymphocytic leukemia.