In parallel, a confirmation of the lack of functional p53 transcriptional activity in both p53mutated primary B-CLL cells and p53mutated MAVER, MEC-1 and MEC-2 cell lines as well as in p53null HL-60 was provided by the use of Nutlin-3, a small molecule activator of p53 [21]. Here, TP53 is linked to B-cell chronic lymphocytic leukemia.