The answer can be a very real threat. In 1999, a patient at a UPenn
clinical trial died after being injected with a virus intended, once
again, to treat a lack of one protein in one organ. His immune system saw
the virus and panicked. As a result, he suffered inflammation of his
whole body, which caused so much strain that he died within a few days of
treatment. The immune system isn't messing around. But it's not done.
Slide 13