Inhibitory molecules such as cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) exist in cytotoxic CD8+T cells within the tumor microenvironment (TME), leading to poor clinical prognosis in LUAD patients (Zhang et al., 2021). Here, PDCD1 is linked to neoplasm.