Only a few biomarkers, such as programmed death-ligand 1 (PD-L1) immuno-histochemistry (IHC) expression, tumor mutational burden (TMB), and circulating tumor DNA (ctDNA), have been investigated in relation to immunotherapy to predict the clinical prognosis of SCLC (3, 8, 9). The gene discussed is CD274; the disease is neoplasm.