CD274 and neoplasm: The KEYNOTE-024 study, together with KEYNOTE-042 study, demonstrated that a PD-L1 tumor proportion score (TPS) ≥50% should act as the cut-off value to select patients with advanced NSCLC to receive first-line pembrolizumab monotherapy, while the standard second-line pembrolizumab monotherapy requires patients to have a TPS ≥1% (57, 62).