ARG1 and neoplasm: In the realm of immune regulation, NETs discharge immunosuppressive factors—including programmed death ligand-1 (PD-L1), reactive oxygen species (ROS), and arginase-1 (ARG1)—to inhibit T cell and natural killer (NK) cell cytotoxicity, while fostering the accumulation of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), thereby remodeling the tumor microenvironment into an immunosuppressive state (77, 78).