CD274 and small cell lung carcinoma: The phase 1/2 CheckMate 032 trial, which explored the efficacy of nivolumab alone or in combination with two different doses of ipilimumab, and the phase 1b KEYNOTE-028 and phase 2 KEYNOTE-158 trials, which examined the efficacy of pembrolizumab for pretreated patients with SCLC with PD-L1 positive tumors, demonstrated efficacy in previously treated SCLC patients (40–42).