Researchers have found that programmed cell death protein-1 (PD-1) and programmed cell death protein ligand-1 (PD-L1) have significantly improved the survival rate of non-small cell lung cancer (NSCLC) [40], while antibiotic therapy led to an imbalance of intestinal flora, which affected the anti-tumor efficacy of immune checkpoint inhibitors (ICI). The gene discussed is PDCD1; the disease is neoplasm.