Fig. 2.

Tissue expression of soluble programmed cell death ligand 1 in patients with small cell lung cancer patients. a: Tissue expression of programmed cell death ligand 1 was higher in the patients without a response to chemotherapy than in the patients with a response to chemotherapy (6.8% ± 3.6%, 4.9% ± 3.6%, P = 0.012). b: Tissue expression of programmed cell death ligand 1 was higher in the dead patients than in the living patients (6.8% ± 3.4%, 4.6% ± 3.7%, P = 0.003). c: There is a linear relationship between serum level of soluble programmed cell death ligand 1 and tissue expression of soluble programmed cell death ligand 1 (r = 0.214, P = 0.034). d: Positively immunohistochemical staining of programmed death ligand 1 in patients with small cell lung cancer patients (400×). e: Negatively immunohistochemical staining of programmed death ligand 1 in patients with small cell lung cancer patients (400×)