IFNG and Guillain-Barre syndrome: Th1 cells, a subset of CD4+T (T helper) cells, are dominant in the inflamed nerves at the acute phase of GBS [8], which could produce IFN-γ as a major pathogenic cytokine in GBS, because increased IFN-γ was seen in the serum of GBS patients at acute phase [10], and higher immunoreactivity for IFN-γ was showed in sural nerves biopsies of GBS patients [11].