More so than brain function, cancer, etc, I feel like we'll look back in a decade or two's time and be shocked at how little we understood autoimmune diseases. Sure, we understand that the immune system adapts in an almost evolutionary way, and can wrongly recognize self-components as foreign. But what signals cause this adaptation? What's causes antibodies to develop against your thyroid, or beta cells, or skin? We understand how so many components of the immune system work, but have so far to go assembling the pieces.