CD274 and non-small cell lung carcinoma: (25) collected paired tissue samples and blood samples from 51 patients with advanced NSCLC to detect the dynamic changes of PD-L1 expression in blood of patients with advanced NSCLC after 2 months of Immune Checkpoint Inhibitors (ICIs) treatment, including the changes of PD-L1 mRNA, exoPD-L1 protein and sPD-L1.