CD8+ T naïve (Tn) cell MMP-Low, CD8+ T effector memory cell MMP-Low, CD8+ T central memory (Tcm) cell MMP-Low, and SCMM-CD8+ Tn cells demonstrated a moderate diagnostic value for SLE, with an area under the curve (AUC) above 0.8. The gene discussed is CD8A; the disease is systemic lupus erythematosus.