ACE2 and infection: Similarly, it has been found that the cellular presence of ACE2 receptors was needed for the entry of RBD-tagged EVs, which is why they were successfully targeted to the lungs and other tissues expressing ACE2 and reduced the infection of SARS-CoV-2 by delivering siRNA incorporated into RBD-tagged EVs, which was conducted in a transgenic hACE2 mouse model.