Conversely, in the phase Ib KEYNOTE-028 trial, patients affected by relapsed SCLC with a combined positive score (CPS, defined as the number of PD-L1-positive cells) ≥1%, who received pembrolizumab, achieved an ORR of 33.3% (95% CI, 16% to 55%) [80]. This evidence concerns the gene CD274 and small cell lung carcinoma.