Stimulated secretion of in vitro-expressed rVWF. Data shows VWF:Ag measured in supernatant divided by total VWF (lysate plus supernatant) following 1 hour of stimulation with PMA or vehicle (DMSO). Data were analyzed using Student t test; DMSO versus PMA (***P < .001; ****P < .0001). Mean values for n = 3 triplicate measurements are shown (bars indicate standard deviation).