Decreased % CD8+ T cells in active DM vs. HC (p < 0.01) and inactive DM (p < 0.05). No difference in PM vs. HC. Increased % activated HLA-DR+ CD3+ T cells in PM, DM vs. HC, regardless of disease activity (p < 0.01). Decreased % IFN-γ+CD8+ T cells in active DM vs. HC and non-active DM (p < 0.01). This evidence concerns the gene IFNG and dermatomyositis.