As we were surprised by these findings, and to ensure that they were not just a peculiarity of WEHI7 thymoma cells, we reproduced most of our experiments in an independent dexamethasone-sensitive lymphoid line11 derived from p53−/− mice that was kindly provided to us by Andreas Strasser (Fig. 1a, right; 1b, right). This evidence concerns the gene TP53 and thymoma.