The autoimmune regulator (AIRE) gene is a gene responsible for autoimmune polyendocrinopathy‐candidiasis‐ectodermal dystrophy. Here we show that AIRE is expressed in human peripheral CD4‐positive T‐cells, and most highly in antigen‐ and interleukin 2‐stimulated T (IL‐2T) cells. Mitogen‐activated protein kinases (MAPKs), including MAPK kinase (MEK) 1/2 and p38 MAPK, were phosphorylated in IL‐2T cells and the expression of the AIRE gene was inhibited by a specific p38 MAPK inhibitor (SB203580), thereby indicating that AIRE gene expression is controlled by the MAPK pathway in IL‐2T cells. These data suggested the possible significance of the AIRE gene in the peripheral immune system.