RUNX1 and lymphoma: Spleens from mice with end-stage disease, which were markedly enlarged due to lymphoma expansion, showed levels of Runx1 deletion significantly lower than normal splenic lymphoid cells from age-matched Mx1Cre+/Runx1fl/fl mice without the Eμ-Myc oncogene, indicating an increased rather than a decreased requirement for Runx1 in primary lymphoma cells (Figure 1C, upper panel and lower right panel).