PTPN22 and myasthenia gravis: Variations in protein tyrosine phosphatase non-receptor-22 (PTPN22), cathepsin 2 (CTSL2), interleukin-4 (IL-4) receptor alpha (IL4Rα), tumor necrosis factor superfamily IIA (TNFRS11A), TNFAIP3-Interacting Protein 1 (TNIP1), Cytotoxic T-Lymphocyte-Associated Protein 4 (CTLA4), CHRNA1 and ecto-NADH oxidase 1 gene (ENOX1) genes are reported to be associated with MG [33, 38, 39].