In similar lines of siRNA therapy, ultrasound-responsive nanobubbles (NB) were used as controlled-release carriers of siRNA CTSK and cerium oxide nanoparticles (CeNPs) to prevent osteoporosis and improve bone mass by downregulating CTSK-induced osteoclastogenesis and upregulating CeNP-induced osteogenesis [30]. The gene discussed is CTSK; the disease is osteoporosis.