An association study of the R620W variant in Hungarian and German MG patients proved that the PTPN22 1858T allele was associated with MG predisposition, only, in the subgroup of nonthymoma patients with detectable ATA (Table 2) [45], leading to conflicting conclusions compared to the French MG study, in which the association was established in the exactly opposite case of non-thymoma patients lacking ATA [21]. The gene discussed is PTPN22; the disease is myasthenia gravis.