Abnormal T cell selection and failure in Treg differentiation are intra-thymoma alterations implicated in the development of thymoma-associated MG, along with an autoimmune regulator (AIRE) deficiency that is suspected to cause the dangerous presentation of muscle autoantigens locally expressed into the thymus, and consequent autoreactivity [17,18,19]. This evidence concerns the gene AIRE and myasthenia gravis.