CD274 and small cell lung carcinoma: In 2019, the FDA approved atezolizumab in combination with etoposide and carboplatin [65] and, in 2020, durvalumab (an IgG1 kappa anti-PD-L1 monoclonal human antibody) in combination with etoposide and carboplatin/cisplatin as first-line treatments for patients with extensive-stage (ES) SCLC (ES-SCLC) (Figure 1) [53].