An antagomir of miR-34a, which blocks its action, restores SIRT1 and SIRT6 in senescent small airway epithelial cells from patients with COPD, reduces markers of cellular senescence (p16, p21, and p53), reduces the SASP response (TNF-α, IL-1β, IL-6, CCL2, CXCL8, and MMP9), and increases proliferation of senescent epithelial cells by reversing cell cycle arrest (Baker et al, 2016b). Here, MMP9 is linked to chronic obstructive pulmonary disease.