PDCD1 and non-small cell lung carcinoma: Anti-PD-1/PD-L1 antibodies have been proved one of the most promising treatments against non-small cell lung cancer (NSCLC); however, whether anti-PD-1/PD-L1 antibodies can provide added benefits for pretreated patients with advanced NSCLC and which patients are most likely to benefit from anti-PD-1/PD-L1 therapy remain controversial.