Pembrolizumab is an antibody ICI that targets the programmed cell death protein 1 (PD-1), and is approved for combination therapy with pemetrexed and platin-based chemotherapy as a first line treatment for non-squamous NSCLC without epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) translocation (Figure 1). This evidence concerns the gene PDCD1 and non-small cell lung carcinoma.