BTK and B-cell chronic lymphocytic leukemia: The presence of TP53 mutations is reported to be the main prognostic factor associated with resistance to conventional therapies and short survival times.[12,13] Ibrutinib covalently bound to cysteine 481 in the ATP binding pocket of Bruton tyrosine kinase, resulting in the inhibition of BCR activation and the induction of apoptosis in mature B-cell maglignancies.[14] Data showing the efficacy of BCR inhibitors in the presence of TP53 mutations is inferred from CLL patients.[15,16] Gordon et.