SMAD7 and osteoporosis: Suppression of miR-92b-3p expression increased NADPH oxidase 4 (Nox4) and NF-κB levels, decreased Smad7, BMP2, and Runx2 gene and protein expressions, and inhibited bone marrow mesenchymal stem cell (BMSC) proliferation and osteoblast differentiation, resulting in more severe osteoporosis.