Figure 3: A schematic representation of antigen cross-recognition leading to autoimmune reactions. The mechanisms of epitope spreading and molecular mimicry are shown. Epitope spreading – several epitopes are generated to form a major antigen that can be recognized, which causes amplification of the autoimmune reaction. Molecular mimicry – structural or conformational similarities or identities of amino acids residues of self-proteins and S. pyogenes proteins are able to trigger an autoimmune reaction.