To test this, we used an ultrasound-microbubble-mediated gene transfer to introduce miR-29b into the liver in mice treated with CCl4. We have previously shown that the use of ultrasound-microbubble-mediated gene transfer is able to effectively deliver Dox-inducible miR-29b plasmid into kidney to block activation of TGF-β/Smad signaling, thereby inhibiting progressive renal fibrosis in rat model [15]. The gene discussed is TGFB1; the disease is renal fibrosis.