CD27 and Graves disease: Subsequent mediation analyses using 2-step MR revealed that “CD25 on CD24+ CD27+ B cells” mediated the causal association between IGP11 and GD, “HLA DR+ T cell%lymphocyte” mediated the causal association between IGP59 and autoimmune thyroiditis, and “B_NGF” mediated the causal association between IGP59 and autoimmune hyperthyroidism.