By employing microarrays and real-time PCR assays in the mouse model of unilateral ureteral obstruction (UUO), abundance of miR-29a, -29b, and -29c is substantially decreased in the fibrotic kidney of UUO wild-type mice but significantly induced in Smad3 knockout (KO) mice in which renal fibrosis was inhibited (Qin et al., 2011). This evidence concerns the gene SMAD3 and renal fibrosis.