Compared with normal mice, the levels of CD4+CD8− single‐positive (CD4+SP), CD4+/CD8+ and CD4+CD8+ DP T lymphocytes were decreased in SLE mice, while the levels of CD8+CD4− single‐positive (CD8+SP) and CD4−CD8− DN T lymphocytes were increased in SLE mice (all P < 0.05). The gene discussed is CD8A; the disease is systemic lupus erythematosus.