Furthermore, CXXC4 is considered as a novel tumor suppressor due to its ability to inhibit the mitogen-activated protein kinases (MAPK) signaling pathway,11 while the downregulation of the MAPK signaling pathway has been proposed to be capable of reducing the expression of programmed cell death 1 ligand 1 (PD-L1) in lung adenocarcinoma cells.12 Here, CD274 is linked to lung adenocarcinoma.