PDCD1 and non-small cell lung carcinoma: Given the above preclinical and clinical data, we conducted a prospective, multicentre, single-arm, phase II trial assessing the safety and efficacy of triple combination of Sintilimab, a PD-1 inhibitor which had been proven to be effective in advanced NSCLC [28, 29], SBRT and GM-CSF as second-line therapy in sensitizing the driver mutation negative metastatic NSCLC.