Our findings may have direct pathophysiological implications for macrothrombocytopenia in patients with congenital GPIb-V-IX deficiency [26], in whom the absence of GPIb (the primary VWF receptor) prevents complete processing of proplatelets to functional discoid platelets in vivo, despite a normal VWF content in vessel walls. The gene discussed is VWF; the disease is Macrothrombocytopenia.