“…Notably, p57 Kip2 downregulation abrogated the ability of PB-derived CD34 + cells to respond to dexamethasone, monitored as a function of their expansion ( Figure 6B). Moreover, we observed that erythroid differentiation was accelerated, as demonstrated by 1.5-and 3-fold increases in GPA expression levels in control-and dexamethasone-treated may be mediated by epigenetic regulators (40)(41)(42)(43), and further investigations of the mechanisms may offer additional insights into the heterogeneity of progenitor cell populations. Finally, our data show the importance of the p57 Kip2 cell-cycle inhibitor in mediating dexamethasone effects during human erythroid differentiation and reveal the critical nature of the p57 Kip2 axis in the dexamethasone responsiveness of patients with DBA.…”