Expression of human and mouse recombinant VWF. Transient transfections of VWF cDNAs were performed in HEK293T, COS-7 and ATt-20 cells, and expressed in serum-free medium, 2 experiments, n = 3 each. Total VWF produced in medium and cell lysates per 10 cm dish was measured via VWF:Ag ELISA, and results normalized to total wild-type VWF equal to 100 for both human (A,C,E) and mouse (B,D,F). *P < .05. ***P < .001.