TP53 and acute lymphoblastic leukemia: The analysis of 265 first-relapse patients enrolled in the German Acute Lymphoblastic Leukemia Relapse Berlin-Frankfurt-Münster 2002 (ALL-REZ BFM 2002) trial for sequence and copy number alterations of the TP53 gene, by using direct sequencing and multiplex ligation-dependent probe amplification, identified copy number and sequence alterations of TP53 in 12.4 % of B-cell precursor ALL samples [56].