You might know Compound E by a different name, cortisol. Cortisol is a steroid that suppresses the immune system. Steroids are the first line of defense against many autoimmune disorders. They are a mixed blessing, as you’ll see later on. For the moment, though, the discovery of steroids in the field of immunology and medicine was analogous to the discovery of a vaccine or antibiotic; they were a tremendous revelation, a response to a vexing problem, but a response that came without an understanding of the underlying mechanism of the disease they were meant to treat—autoimmunity.
