[8] Lunatic Fringe responds to certain threshold ratios of retinoic acid and FGF-8 in order to mark the anterior boundary of somites while another transcription factor, Hairy, responds to different threshold ratios of retinoic acid and FGF-8 to form the posterior boundaries of somites.

[10] Clinically, spondylocostal dysostosis presents as a shortened neck and trunk relative total height and a mild form of scoliosis.

Somites give rise to the skeletal muscle, the axial skeleton, the tendons, and the dorsal dermis.

Lunatic fringe responds to the lower concentration of FGF8 in the anterior and leads these cells to their developmental fate.

Mutation of the Lunatic Fringe gene can cause severe spondylocostal dysostosis, which involves vertebral segmentation defects and rib abnormalities.