HLA-DRB1 and myasthenia gravis: Results from HLA-DRB1*09 and DQB1*03 suggest a negative correlation with the prevalence of MG, which contradicts the positive association described in Fekih-Mrissa et al. [15], Xie et al. [17], Fernández-Mestre et al. [18] (Table 8, Figure 9, Figure 10).