CD4 and myasthenia gravis: Indeed, a significant defect in Treg suppressive function has been described in MG [38] and in its animal model EAMG [27, 39]; a reduction in the frequency of CD4+CD25+FoxP3+ cells combined with decreased suppressive activity in EAMG has also been found [39], and a severe functional defect and decreased FoxP3 expression in thymic Tregs of MG patients have been reported [40].