Distribution of FLNa and VWF in mature MKs cultured from CD34⁺ blood cells of P1. (A-B) Mature MKs from a control donor with the concomitant presence of FLNa and VWF also in the proplatelets. For P1 (C-F), MKs are shown normally containing VWF and FLNa (C), whereas others contain decreased amounts of FLNa (D) or are devoid in FLNa (E-F). Arrows indicate the presence of MKs devoid in FLNa. In panel E, the right side shows the presence of a nucleus, confirming the identification of a cell as an MK by refractory microscopy, in other cells, nuclei are labeled by 4,6-diamidino-2-phenylindole (blue).