PTPN22 and autoimmune disease: In addition, we detected some rare variants in the immune-associated genes including PTPN22, NFKB1, TLR2, and CXCL10. There have been growing evidences on the role of autoimmunity and immunological mechanisms in the development of MD as follows: (1) The increased prevalence of autoimmune disease among MD patients, (2) The elevated levels of autoantibodies and immunocomplexes in MD patients, (3) The association of MD with HLA-types and genetic polymorphisms, and (4) The positive response to steroid (52–54).