TβRI inhibition restores bone mass in Nf1flox/−;Col2.3Cre mice. (A) (Top) The percentage change in BMD of the distal femur was determined by pDXA before and after 4 weeks of treatment with vehicle or SD-208 (60mg/kg/d). n = 7 to 12 mice per group. *p < 0.05, **p < 0.01, ***p < 0.001. (Bottom) Trabecular bone volume fraction (BV/TV) was quantified by µCT. n = 7 to 12 mice per group. *p < 0.05, **p < 0.01. (B) Representative µCT reconstructed femora in longitudinal (top) and transverse (bottom) cross-sections after 4 weeks treatment with vehicle or SD-208 treatment. (C) Representative longitudinal sections of H&E stained femora, ×25 magnification. (D) The osteoblast number per millimeter of bone surface was quantified by manually counting osteoblasts on H&E-stained sections (×200 magnification). n = 7 to 12 mice per group. *p < 0.05, **p < 0.01, ***p < 0.001.