Inhibitory pathways, like programmed cell death-1 (PD-1), CTLA-4, and lymphocyte activation gene-3 (LAG-3), are crucial for maintaining the balance of tolerance to self and prevention of autoimmune pathology through the inhibition of overactive T cells (59, 60)., Immune checkpoint blockade reinvigorates exhausted T cells and enhances anti-tumor immune responses. The gene discussed is PDCD1; the disease is neoplasm.