CTLA4 and myasthenia gravis: The results from ELISA, which was employed to detect the expressions of serum-related factors and concentration of cytokines, indicated (Fig. 3) that the expressions of serum AchR-Ab, titin-Ab, and RyR-Ab in the MG group were significantly higher than those in the control group, while the expression of serum CTLA-4 was reduced (P < .05).