Pneumonitis has been identified in less than 1% of patients treated with anti–CTLA-4 antibody [49,51], in 1–6% of those treated with anti–PD-1/anti–PD-L1 (1–2% for melanoma, 3–6% for lung cancer) [52,53,54,55,56] and in 10% of patients during combined ICIs treatment [57,58]. Here, CTLA4 is linked to lung carcinoma.