Either fibrinogen, FN, vWF, or PBS was incubated with AAV9 at 4 °C for 2 hours, and were then transferred into the upper chamber of transwell with Caco-2 cells. At the time points of 30 minutes, 2-, 6-, and 24- hours, the media was collected from the lower chamber and was tested by qPCR for the AAV9 virus genome. The experiment was independently performed twice. Each experiment contained a 3-replicated transwell. A representative experiment is shown.