TP53 and B-cell chronic lymphocytic leukemia: Recently, we have shown that PBOX-15 induces apoptosis in ex vivo B-cell chronic lymphocytic leukaemia (CLL) cells harbouring poor prognostic indicators and fludarabine resistance-associated p53 deletions (McElligott et al, 2009), and in imatinib-resistant chronic myeloid leukaemia (CML) cells (Bright et al, 2010).