MiR-19b, a member of miR-17-92 cluster, has been widely involved in cardiomyocyte proliferation [28] and myocardial fibrosis [29], miR-19b expression is reduced in pulmonary fibrosis, which is involved in fibrosis through negative regulation of DNA methyltransferase-1 [30]. Here, DNMT1 is linked to pulmonary fibrosis.