Effective blockade of PD-1 and PD-L1 interaction could provide a promising strategy of immunotherapy for tumors expressing PD-L1.129 Expression of PD-L1 on tumor and immune cells has been selected as an important biomarker predicting the therapeutic response to anti-PD-1/PD-L1 treatment in patients with SCLC.130. This evidence concerns the gene CD274 and small cell lung carcinoma.