For NSCLC patients with all PD-L1 categories, the KEYNOTE-189 study demonstrated for the first time that the addition of pembrolizumab to standard chemotherapy resulted in significantly longer OS and PFS than chemotherapy alone in patients with metastatic non-squamous NSCLC without previous treatment or EGFR or ALK mutations, regardless of PD-L1 expression (26). Here, CD274 is linked to non-small cell lung carcinoma.