CTLA4 and pneumonitis: To that extent, an important strength of this work was that all patients received ICIs targeting the PD-1—PD-L1 axis, whereas the aforementioned publications utilized a mixture of anti-PD-1/PD-L1 agents alone, anti-CTLA-4 compounds alone, and dual immune checkpoint blockade [although it has been suggested that PD-1 and PD-L1 inhibitors have differential rates of pneumonitis (19)].