ALK and non-small cell lung carcinoma: The results of the KEYNOTE‐024 trial and KEYNOTE‐042 trials showed that pembrolizumab, a monoclonal antibody against PD‐1, was more effective than conventional platinum‐based combination chemotherapy as a first‐line treatment for advanced NSCLC expressing PD‐L1 on the tumor cells, which are negative for epidermal growth factor receptor gene (EGFR) mutation and anaplastic lymphoma kinase gene (ALK) rearrangement.4, 5