Nonetheless, it would be important to clarify two points. First, in Figure 1d the total number of CFUs (per 500 cells plated) seems not to change independent on whether freshly isolated, plastic culture or ECM culture dish are employed. However, Figure 1g seems to contradict these data since clearly more CFUs can be recovered from freshly isolated CD34+ cells than from ECM cultured cells. Could the authors provide an explanation for this apparent discrepancy?
Second, it seems quite puzzling to me that the expansion of erythroid progenitors in ECM culture conditions occurs mostly in the non-adherent fraction. If ECM scaffolds play a major role in commitment towards the erythroid lineage one would expect to see the most significant expansion in the fraction that is directly in contact with the ECM. The authors do not discuss this finding.
Very minor: Three references (Naik and Parise, 1997; Ficko, 2008) and (Eshghi et al., 2007) were not appropriately formatted, most likely during the uploading process.