CD274 and small cell lung carcinoma: The PD-L1 inhibitors atezolizumab and durvalumab, in combination with platinum and etoposide, have significantly prolonged overall survival (OS) and reduced the risk of death in SCLC patients in IMpower 133 and CASPIAN studies, and are approved as standard first-line treatment of extensive-stage SCLC in 2019 and 2020, respectively [3, 4].