Cutting edge commentary: A Copernican Revolution? Doubts about the danger theory

The immune system is often said to function by "self-nonself" discriminatio n. Recently, some have argued that it actually detects "danger" or "strange rs." There are problems with all of these points of view. Given that the im mune system has been cobbled together throughout evolution and uses a diver se array of innate and adaptive defense mechanisms, it may not be possible to account for immunity within one "paradigm" or another.