In the univariate analysis in the chemoimmunotherapy cohort, CD8-high (P = 0.0060) showed a significant association with PFS, while ECOG-PS ≥ 1 (P = 0.0014) and SCLC-P (vs SCLC-I) (P = 0.037) had an unfavorable association, and clinical stage (C-Stage ≥ IVB) (P = 0.070) and SCLC-N (vs SCLC-I) (P = 0.068) showed an unfavorable trend with PFS (Table 2). Here, CD8A is linked to small cell lung carcinoma.