PDCD1 and neoplasm: Factors that affect the choice of treatments in NSCLC that lack a driver mutation include the level of PD-L1 expression on cancer cells, the extent of the disease and the tumor's histological characteristics. Specifically, patients with metastatic NSCLC and PD-L1 expression ≥ 50% are typically offered monotherapy with the anti-PD-1 antibody Pembrolizumab.