Interestingly, thymic tumours in Tdp2−/−Atm−/− mice display identical characteristics to those of Atm−/− animals, with a very aggressive form of T-ALL associated to recurrent clonal genome rearrangements enriched at loci undergoing V(D)J recombination (Figs. 2–3; Supplementary Fig. 2–3 and Supplementary Table 1). This evidence concerns the gene ATM and acute lymphoblastic leukemia.