In addition, downregulation of the Ptcra (Pre-T-cell Receptor alpha) mRNA levels could be observed upon Zeb2 overexpression in the p53 null thymic tumours (Supplementary Fig. 7c), similar to what is previously seen in human5 and mouse24, 25 immature/ETP-ALL. Here, TP53 is linked to acute lymphoblastic leukemia.