However, another series of 29 metastatic NSCLC patients given thoracic RT and PD-1/PD-L1 and/or CTLA-4 inhibitors identified 1 case of possibly treatment-related grade 5 pneumonitis in a patient who received 20 Gy over 5 fractions of thoracic RT initiated 1 month after the last dose of anti-PD-1 therapy [125]. Here, CTLA4 is linked to non-small cell lung carcinoma.