SIRT1 and leukemia: [4] In a subset of leukemia cells, impairment of the function or expression of C/EBPα results in a differentiation block in leukemic blast cells [33]–[35], which might possibly be reversed by the upregulation of C/EBPβ [36]. Here, CREBs-mediated transcriptional activation of C/EBPβ was shown as one of the switching mechanism for ‘emergency’ granulopoiesis. Recent reports have demonstrated that STAT3 and sirtuin-1 were also involved in the upregulation of C/EBPβ during granulopoiesis under stressed conditions [37]–[38].