Undoubtedly, ibrutinib has exceptional activity in patients with RR CLL, as well as in untreated patients with genetic abnormalities that predict chemoresistance (i.e., TP53 deletion or mutation), where a significant reduction in organomegaly and LN size is observed in most cases (Byrd et al., 2014). This evidence concerns the gene TP53 and B-cell chronic lymphocytic leukemia.