['Autoimmune gastritis (AIG), an organ-specific autoimmune disease, is accompanied by achlorhydria, pernicious anemia, gastric carcinoid tumors, and gastric cancer. Patients with AIG initially respond to corticosteroids but have a great potential to relapse after treatment is withdrawn. This study examines the roles of cytokines in order to identify potential therapeutic options for AIG patients.', 'Using a mouse model of AIG, we monitored disease progression and administered antibodies in vivo to block cytokines.', 'We developed a mouse model of AIG with early onset and rapid progression in which neonatal thymectomy (NTx) was performed on programmed cell death 1-deficient (PD-1(-/-) ) mice on the BALB/c background. Using NTx-PD-1(-/-) mice, we found that in AIG lesions, interferon-γ, and tumor necrosis factor (TNF)-α together with interleukin-21 (IL-21) were highly expressed in the inflamed gastric mucosa. In addition, as with the injection of dexamethasone, in vivo administration of either anti-TNF-α or anti-IL-21 suppressed the development of AIG in NTx-PD-1(-/-) mice.'] Are interleukin-21 and tumor necrosis factor-α critical for the development of autoimmune gastritis in mice?