In this report we have not defined the mechanism that drives up-regulation of PI3K/AKT signalling in Eμ-Myc/c-Rel−/− lymphomas, although one possibility is that this results from the loss of CHK1 protein that we see in Eμ-Myc/c-Rel−/− lymphomas [20]. The gene discussed is CHEK1; the disease is lymphoma.