FAS and Guillain-Barre syndrome: Several other gene polymorphisms such as HLA B54 [55], HLA-Cw1 [55], HLA class II [56], CD1 [65], MBL2 [66], HLA-DRB1*0701 [67], Fas/CD95 [56], FcγR2A [67], FcγR3A [68], FcγR3B [68], SH2D2A [69], immunoglobulin KM gene [70], GR haplotypes [71], and MMP9 [72] are also studied and associated with the development or severity of GBS.