Programmed death 1(PD-1)/programmed ligand 1 (PD-L1) immune checkpoint inhibitors (ICIs) has shown remarkable efficacy in the treatment of cancer. The predictive value PD-L1 expression for ICIs advanced non-small cell lung cancer (NSCLC) raise wide attention, also with some controversies. We combined existing data by meta-analysis to analyze patients different levels, and provide a basis select...