CD19 and myasthenia gravis: The expression of OX40 on CD4+ T lymphocytes was increased (P ≤ 0.001) (Figures 1(a) and 1(b)), and the expression of OX40L on CD19+ B cells and CD14+ monocytes was increased in the peripheral blood of MG patients at baseline compared with that of HC (P = 0.011 and P = 0.026, respectively) (Figures 1(a), 1(c), and 1(d)).