Excitingly, further studies in a mouse model have recently demonstrated that FNDC3B is required for normal calvarial bone formation and negatively regulated calvarial cell differentiation through inhibition of BMP/Smad signaling. fndc3b-deficient mice have multiple cranial and skeletal malformations, such as craniosynostosis-like premature calvarial ossification, and skeletal deformities in the anterior fontanel and femurs.