B7-1 and programmed cell death-ligand 1 in primary and lymph node metastasis lesions of non-small cell lung carcinoma.

PD-1 inhibitors inhibited PD-1/PD-L1 binding but not PD-L1/B7-1 binding. These results demonstrated that the intratumoral ratio of B7-1 positive T cells in NSCLC tissue could be involved in the therapeutic efficacy of PD-L1 inhibitors. This study focused on lymph node metastasis but other sites of distant metastases should be explored by further analysis.