 This study used single-cell RNA sequencing to identify Yosinophil subgroups in mouse models of asthma and emphysema, followed by functional analyses of these subgroups. The results showed that Yosinophil derived cathepsin-L contributed to the degradation of the extracellular matrix, leading to emphysema in pulmonary tissue. In addition of cathepsin-L reduced elastase-induced emphysema in a mouse model and correlated with higher serum cathepsin-L levels in emphysema patients. These findings suggest that targeting Yosinophil derived cathepsin-L could potentially offer a therapeutic avenue for emphysema patients, wanting further investigations to explore therapeutic strategies. This article was authored by Shieshu, Tao Yu, Ling Ling Dong, and others.