Anti-IL-21 Antibody represents a highly specialized neutralizing monoclonal antibody specifically engineered to target the pro-inflammatory cytokine interleukin-21 (IL-21) with exceptional binding affinity. It effectively facilitates the measurable blockade of the IL-21/IL-21R signaling axis across various preclinical experimental models to evaluate the suppression of Th17/Tfh-mediated immune responses and the reduction of thyroid-specific autoantibodies during strictly monitored laboratory observation periods and functional immune cell assays.