PRF1 and systemic lupus erythematosus: Similar immune alterations have been described in systemic autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis [17], where CD28 + granzyme K-high, perforin-low CD8 + T-cells infiltrate inflamed tissues and secrete proinflammatory cytokines such as IFN-γ [17].