Investigating rare diseases gives researchers more clues about how the healthy immune system functions.
The immune system's goal is to protect the body against invaders either from without, such as microbes, or from within, such as cancers and different types of neoplastic transformation.
The body's immune system is like any other system of the body. Each of them have their vital function for the human host.
Your immune cells are like a circulating nervous system. Your nervous system in fact is a circulating nervous system. It thinks. It's conscious.
The AIDS crisis has brought us a consciousness of the immune system as the most important health maintenance element, and a consciousness of how it is under attack.