Among various malignant tumors, the incidence and mortality rate of lung cancer has steadily ranked the first and continues to rise. Among lung cancer patients, 85% of them have already lost the chance of surgery when diagnosed and can only undergo radiotherapy or other conservative treatments. In recent years, targeted therapies (targeted drugs targeting EGFR, ALK and other gene-sensitive mutations) have enabled some patients with advanced non-squamous non-small cell lung cancer (adenocarcinoma and large cell carcinoma) to not only extend their survival but also obtain a better quality of life, which is greatly recognized by clinical workers and patients. However, in recent years, there has been no breakthrough in advanced squamous lung cancer, and the treatment is still limited to chemotherapy and radiotherapy, and the treatment is very tricky and poor after the failure of advanced radiotherapy and chemotherapy. A set of data from this year’s ASCO annual meeting may bring light to patients with advanced squamous cancer. A randomized phase III clinical trial, CheckMate 017, designed to explore the efficacy of comparing the anti-PD-1 (programmed death protein) drug Nivolumab with docetaxel in patients with previously treated advanced or metastatic squamous non-small cell lung cancer (NSCLC), showed that Nivolumab compared favorably with docetaxel in terms of overall survival (42% vs. 24%), progression-free survival (21% vs. 6%), median survival time (9.2 months vs. 6.0 months), objective remission rate (20% vs. 9%), and adverse events (7% vs. 55%) were significantly better than previous second-line standard of care docetaxel. Interestingly, the efficacy of Nivolumab in squamous lung cancer did not correlate significantly with positive PD-L1 expression. Due to the excellent performance of Nivolumab in squamous lung cancer and the current lack of effective targeted therapy for advanced squamous lung cancer, Nivolumab has been approved for marketing by the US FDA. In patients with non-squamous non-small cell lung cancer, Nivolumab has also shown good therapeutic efficacy. Unlike squamous lung cancer, the higher the PD-L1 expression in non-squamous non-small cell lung cancer, the better the efficacy shown by Nivolumab. In patients with previous treatment failure in non-squamous non-small cell lung cancer (including those who had been treated with TKI and crizotinib), Nivolumab compared with docetaxel resulted in an overall median survival extension of 3 months (12.2 months vs. 9.4 months), and in patients with high PD-L1 expression, the median survival was 17.2-19.4 months, an extension of 8-10 months. This is an unprecedented breakthrough! Thus, Nivolumab is also expected to become the standard second-line treatment for non-squamous non-small cell lung cancer.