Now, genetic mutations, for example in the DNA that codes for MHC membrane proteins may lead to autoimmunity as we just discussed. Now let's move on to factor number two that might lead to autoimmunity infections by pathogen. So let's suppose some type of pathogen infects our body and infects a cell. So here we have an infected cell. Now, what the infected cell will do is it will take a certain antigen that came from that pathogen and it will display it on this MHC protein complex. So the major histocompatibility complex as shown.