The results of this SLR show that mOS values in the post-approval era tended to be longer than those in the pre-approval era for patients with advanced/metastatic NSCLC in the first-line setting, including NSCLC patients with PD-L1-positive tumors who received anti-PD-(L)1 monotherapy and NSCLC patients with non-squamous cell carcinoma who received anti-PD-(L)1 combination therapy. Here, CD274 is linked to squamous cell carcinoma.