CD274 and small cell lung carcinoma: The current first-line SOC treatment for SCLC is platinum-based chemotherapy (cisplatin plus etoposide or carboplatin plus etoposide; CE) with concurrent radiotherapy for patients with limited-stage SCLC (LS-SCLC), followed by prophylactic cranial irradiation for patients who experience a complete response [7, 8], and CE with a programmed death-ligand 1 (PD-L1) inhibitor for patients with extensive-stage SCLC (ES-SCLC) [8].