AIRE and autoimmune disease: In particular, defective expression of the autoimmune regulator (AIRE) and the forebrain-expressed zinc finger 2 (Fezf2) has been observed in the majority of thymomas, potentially contributing to compromised negative selection of self-reactive T cells, as well as defective positive selection of immunosuppressive central regulatory T cells, thereby offering a partial explanation for the link between autoimmune diseases and thymomas (114).