Besides CD8+ NKG2D+ T cells and IFN-γ, some inflammatory cells and cytokines also play a significant role in the immune pathogenesis of alopecia areata, such as dendritic cells, CD4 + T cells, NK T cells, mast cells and eosinophils, and other cytokines such as IL-2, CXCLs, and TNF-α. This evidence concerns the gene KLRK1 and alopecia areata.