In order to reveal the latent mechanism underlying the correlation between PD-L1 induction and CD8+ TIL infiltration, the mRNA levels of PD-L1, CD8 and IFN-γ were accessed by RT-PCR in 40 NSCLC specimens, showing that IFN-γ is significantly associated with PD-L1 and CD8 gene expression. The gene discussed is CD274; the disease is non-small cell lung carcinoma.