In addition to increased expression of miR-570-3p, lungs from patients with COPD also expressed increased markers of cellular senescence, with reduced gene expression of sirtuin-1 and CDK4 along with elevated p21 and the SASP proteins MMP-9 and CXCL8 (Fig. 2E–I). Here, MMP9 is linked to chronic obstructive pulmonary disease.