SIRT1 and autoimmune disease: Silencing these proteins restores the antitumor function of NK cells.54,55 Within adaptive immunity, SIRT1 is essential for T cell activation and peripheral tolerance, preventing autoimmune diseases by suppressing AP-1 transcription and IL-2 production in the absence of CD28 costimulation.56 Furthermore, both SIRT1 and SIRT7 regulate B cell class-switch recombination (CSR), influencing immunoglobulin (Ig) maturation.57 Overall, the sirtuin family acts as a critical regulator of immune aging by fine-tuning metabolic and inflammatory pathways in multiple immune cell types.