And this can lead to many problems because for example, as we know, the process of breathing involves the diaphragm and the diaphragm is in fact a skeletal muscle. So in a person that has myosthenia gravis, if they begin to exercise very vigorously, they will have problems breathing because this autoimmune disease affects the weight of ability that we actually contract our skeletal muscle. Now, although this topic of autoimmunity is heavily researched, we still actually do not quite understand how autoimmunity actually takes place. But we do have some idea. So some possibilities that basically that cause autoimmunity might be a genetic mutation on our DNA in a section that codes for some type of important component of our immune system. For example, the major histocompatibility complex as we'll see in just a moment.