In all tissues, HLA-DQB1 (median p = 1.99 × 10−68, 11 tissues), HLA-DRB1 (median p = 7.08 × 10−62, 25 tissues), HLA-DRB6 (median p = 9.54 × 10−41, 21 tissues), CYP21A1P (median 7.84 × 10−29, 14 tissues), HLA-J (median p = 2.82 × 10−18, 30 tissues), HLA-DQA1 (median p = 1.53 × 10−27, 19 tissues), and ATF6B (median p = 3.1 × 10−27, 16 tissues) showed the most significant pleiotropic associations with MS. The gene discussed is HLA-J; the disease is myeloid sarcoma.