These results suggested that miR-23a-5p could directly bind to the 3′-UTR of AGER. In addition, fluorescent in situ hybridization (FISH) (Fig. 3F–G) and rt-qPCR (Fig. 3H) in lung tissue of COPD model mice showed that miR-23a-5p levels were indeed significantly lower in lungs of COPD mice compared to controls. The gene discussed is AGER; the disease is chronic obstructive pulmonary disease.