The level of FOXP3 has shown its statistically prognostic value in SCLC, especially among patients without metastasis.64 However, in SCLC, few studies examined the prognostic value and clinical significance of Gal-9 in combination with other immune biomarkers or immune cells, including PD-1, PD-L1, CD3, CD4 and FOXP3. The gene discussed is CD4; the disease is small cell lung carcinoma.