CD8A and systemic lupus erythematosus: Hence, its signals may promote cytotoxicity in the cytotoxic CD4+ subset or reverse the defective phenotype of CD8+ cytotoxic T lymphocytes of patients with systemic lupus erythematosus [31, 32]; however, in cancer-specific settings its expression is also related to exhaustion or a suppressive capacity of CD8+ T cells [33, 34].