Romiplostim-induced an increase in immature MKs. (A) Quantification of BM MKs as observed by electron microscopy, per surface unit (s.u.; 12 945 μm²). Each bar represents the mean ± SEM of 3 BMs, for a total number of 99-205 counted MKs. (B) Classification of the MKs according to their maturation stages: stage I (presence of granules), stage II (developing DMS not yet organized), stage III (DMS organized in platelet territories). Data are represented as the percentage of total MKs. (C) Quantification of naked MK nuclei inside the BM. Each bar represents the percentage of naked nuclei relative to the total number of MKs counted.