Considering the data so far obtained, that is: (i) HSP70/HSF1 overexpression in CLL cells, especially at the beginning of disease progression in those patients who failed ibrutinib, and (ii) the efficacy of HSP70 or HSF1 inhibitors in inducing death in CLL cells, we hypothesized an efficacy of these molecules in inducing apoptosis, even in cells from patients resistant to ibrutinib. This evidence concerns the gene HSF1 and B-cell chronic lymphocytic leukemia.