Meanwhile, PD-L2 is expressed in lung cancer (Fernandez et al. 2022), and high PD-L2 expression is associated with smoking, poor overall survival (OS) and disease-free survival (DFS) in patients with lung adenocarcinoma (LUAD) (Takamochi et al. 2022). The gene discussed is PDCD1LG2; the disease is lung adenocarcinoma.