Effect of ER stress on MKS derived from CD34⁺ cells from healthy donors. (A) Representative microscopic images of the CD34⁺ cells isolated from the peripheral blood of healthy donors over the 15-day culture period at original magnification ×20. The ER stressor, thapsigargin (125 nM), was added to the culture at day 7 and cultured for another 7 days. (B) RNA expression: cell culture from thapsigargin-treated CD34⁺-derived MKs (n = 7). (C) (1) Western blot of the thapsigargin-treated CD34⁺ cells–derived megakaryocytes (n = 3 in triplicate) and (2) densitometry for the blots. Densitometry was performed using the ImageJ software (∗∗∗∗P < .0001; ∗∗P < .01, when compared with untreated controls).