Autoreactive T lymphocyte activation can lead to abnormal numbers of CD4+ and CD8+ T cells, and these changes can further induce SLE; in SLE patients, the number of CD4+ T cells was decreased, the number of CD8+ T cells was increased, and the ratio of CD4+/CD8+ T cells was continued to decline 26. Here, CD4 is linked to systemic lupus erythematosus.