In agreement with this theory, this study demonstrated that CD3+, CD4+, and CD4+/CD8+ levels of patients treated using the combined regimen were higher than patients who received EP chemotherapy alone, consistent with previous research.25,26 Our results further confirm, that the combination of Tislelizumab and chemotherapy can improve the immune function of patients with SCLC. Here, CD8A is linked to small cell lung carcinoma.