VWF and von Willebrand disease (hereditary or acquired): VWF is a prerequisite for the formation of its storage vesicles, WPBs, proved by the lack of WPBs in ECFCs of a previously reported type 3 VWD patient as well as the current type 3 IP VWD, or VWF knock-out animal models [16,43,44,45,46,47].