administration of AG490 (JAK2 inhibitor) or HJC0152 (STAT3 inhibitor) significantly reduced both the frequency and absolute cell number of Siglec-F+ neutrophils in the lungs of PPE-treated mice (Fig. S8A, B), and this reduction was accompanied by marked alleviation of emphysema symptoms, as assessed by MLI (Fig. 8C, D). Here, JAK2 is linked to pulmonary emphysema.