CD4 and myasthenia gravis: To characterize the relationship among the FoxP3+ Treg/CD4+ T cell ratio, Tr1 cell/FoxP3+ Treg ratio, Tr1 cell/FoxP3+ Treg ratio and the anti-AChR Ab concentration, we further dividing the MG patients into 2 subgroups based on the median of anti-AChR Ab concentration as cut-off values.