RUNX1 and leukemia: While loss of Necdin did not affect the number of early apoptotic (Annexin V+/PI−) leukemia cells expressing AML1-ETO9a (Figure 6D), the number of late apoptotic cells (Annexin V+/PI+) was significantly increased in Necdin null group compared with wild type group following high concentration of AraC treatment (Figure 6E).