VTCN1 and myasthenia gravis: <h4>Objectives</h4>This study aimed to systematically investigate the dynamics changes in membrane-bound B7-H4 (mB7-H4) expression and soluble B7-H4 (sB7-H4) levels in the peripheral blood of patients with acetylcholine receptor antibodies (AchR-Ab)-positive myasthenia gravis (MG) across different disease phases, and to explore their clinical significance.<h4>Methods</h4>AchR-Ab-positive MG patients at baseline, relapse, and remission stages, along with age- and sex-matched healthy controls (HCs), were enrolled.