The present study is the first to report the following characteristic features of γδ T cells in MS: (1) a decrease of Vδ2+, Vδ2+Vγ9+ cells, and IFN-γ+Vδ2+ γδ T cells; (2) negative correlations between the percentages of Vδ2+Vγ9+ cells in γδ T cells and disease severity as determined by EDSS scores and MSSS; and (3) lack of positive correlations between the percentages of Vδ2+, Vδ2+Vγ9+, and IFN-γ+Vδ2+ cells in γδ T cells and of CD3+ T cells with Treg cell percentages in CD4+ T cells in HCs. Here, IFNG is linked to myeloid sarcoma.