The predictive values of tumor programmed death ligand-1 (PD-L1) expression 23, CD8+ tumor-infiltrating lymphocytes (TILs) 23, and high tumor mutational burden (TMB) 24 density have been demonstrated to be associated with ICIs efficacy, however, the immune composition and expression of potentially actionable immunostimulatory targets in SCLC are poorly understood. This evidence concerns the gene CD8A and small cell lung carcinoma.