This frequency is significantly higher than published safety data of PD-1 checkpoint blockade trials [3, 4, 18] and also significantly higher than in a cohort of 40 metastatic NSCLC patients treated with PD-1 inhibitors at our center (all grades 25.49%, grade 3 or 4 at 9.8%). The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.