For most of the 20th century, scientists pictured the immune system as the body’s ever-vigilant army—standing guard against germs, viruses, and rogue cells. Yet one question remained: What keeps this army from mistakenly attacking the body itself?
For millions with autoimmune and inflammatory diseases such as Type 1 diabetes or lupus, the question is personal—these life-long illnesses bring painful symptoms and harsh immune-suppressing treatments.





