ASIA/Schoenfeld syndrome is one of my concerns.
Hi Nursej22, As far as aspects of immunology that we still don't understand - there are many. For example, autoimmunity. Sure, we know what's happening, but why? Is it genetic, environmental? Both? Neither? There is some genetic component to a lot of autoimmune disorders, but not all. Roles and functions of cells, receptor function and identities are being discovered every day. Even lymph vessels were discovered fairly recently in the brain.