A second mechanism thought to cause autoimmunity is described as molecular mimicry. In this model it is possible for certain innoculants to induce immune responses to protein sequences that are similar to normally occurring tissue. The best example of this is the relationship between acquired immunity to German measles from vaccination and the autoimmune disease of Ankylosing Spondylitis. This causes the acquired immunity of the vaccination to attack the normal occurring tissue in the body thinking that is a foreign protein.