The AUC value for risk score model, Gal-9 on TILs, CD4, and PD-L1 on TILs were 0.671, 0.622, 0.621, 0.644, respectively (figure 4D), which highlighted that the risk score model performed better than other immune biomarkers in the prediction of prognosis in stage I–III SCLC. This evidence concerns the gene LGALS9 and small cell lung carcinoma.