There are two reasons for this: first, both PD-L1 expression and TMB, the two major biomarkers for immunotherapy, are significantly higher in lung squamous carcinoma than lung adenocarcinoma; second, previous studies reported the majority of genomic alterations are distinct between squamous and adenocarcinoma NSCLC since they have different origins (26, 27). This evidence concerns the gene CD274 and lung adenocarcinoma.