Interestingly, it was found that epithelial, sputum and plasma miR-221-3p expression was prominently decreased in patients with asthma, and the decreased expression of miR-221-3p might protect against airway eosinophilic inflammation by upregulating anti-inflammatory chemokine CXCL17, indicating that epithelial and sputum miR-221-3p are novel biomarkers for airway eosinophilic inflammation in asthma [14]. Here, CXCL17 is linked to asthma.