CTLA4 and idiopathic pulmonary fibrosis: While the relationship between immune checkpoints and IPF has not been explicitly reported in these studies, prior research has demonstrated that combining PD-1/PD-L1 and anti-CTLA4 inhibitors may enhance treatment efficacy, not only in non-small cell lung cancer but also in small cell lung cancer, thereby presenting a promising first- or second-line treatment option (65, 66).