DNMT3B and thymoma: After stratification of MG patients into three subgroups according to thymic pathology (normal thymus, thymic hyperplasia and thymoma), the comparison of each of the three subgroups with controls revealed a significant association of the DNMT3B-579T allele with increased thymoma risk (OR = 1.5; 95% CI = 1.1-2.1, P = 0.01).