Current researches have reported the correlations between GNLY or CD8 T cells and several autoimmune diseases, such as differential expressions of GNLY in rheumatic arthritis and healthy state, an association of GNLY expressions in CD8 cells and steroid resistance in polymyositis, an association of disease flares and proportions of activated CD8 T cells in systemic lupus erythematosus (32–34). This evidence concerns the gene CD8A and polymyositis.