Our findings echo a recent preclinical analysis where bendamustine-induced DNA damage was enhanced because of fludarabine-mediated inhibition of DNA repair and abrogated the protective effects of stroma.43 Importantly, we show that MLN4924 in combination with bendamustine did not enhance apoptosis of the CLL cells with del(17p), suggesting that although this is a promising therapeutic strategy, it is not relevant to CLL with defective p53. The gene discussed is TP53; the disease is B-cell chronic lymphocytic leukemia.