Validation cohorts including our biobank confirmed that the AXL expression significantly correlated with expression of genes encoding programmed death-ligand1 (PD-L1) and CXC chemokine receptor 6 (CXCR6) in lung adenocarcinoma, especially in epidermal growth factor receptor (EGFR) mutation-positive adenocarcinoma. This evidence concerns the gene CD274 and lung adenocarcinoma.