CD4 and small cell lung carcinoma: Lung Cancer Fang No. 1 combined with PD-1/PD-L1 inhibitor chemotherapy compared with using PD-1/PD-L1 inhibitor chemotherapy can decrease CYFRA21-1, CA125, and VGEF levels, increase CD4+, CD3+, and CD4+/CD8+ levels, and improve clinical symptoms (including cough, expectoration of sputum, hemoptysis, chest tightness, fatigue, chest pain, and fever) in SCLC patients (306).