VWF and von Willebrand disease 3: In this study, we aimed to elucidate disease genetics etiology in one type 3 VWD index patient (IP), who was found to be without any causative mutations by routine genetic analysis, through screening of the VWF deep intronic region by next-generation sequencing (NGS) and an in-depth study of the patient-derived endothelial colony-forming cells (ECFCs), which are true-to-nature cell models [29].