Forkhead box C1, also known as FOXC1, is a protein which in humans is encoded by the FOXC1 gene.
This gene belongs to the forkhead family of transcription factors which is characterized by a distinct DNA-binding fork head domain. The specific function of this gene has not yet been determined; however, it has been shown to play a role in the regulation of embryonic and ocular development. Mutations in this gene cause various glaucoma phenotypes including primary congenital glaucoma, autosomal dominant iridogoniodysgenesis anomaly, and Axenfeld-Rieger anomaly.
FOXC1 and its close relative, FOXC2 are both critical components in the development of the heart and blood vessels, as well as the segmentation of the paraxial mesoderm and the formation of somites. Expression of the Fox proteins range from low levels in the posterior pre-somitic mesoderm (PSM) to the highest levels in the anterior PSM. Homozygous mutant embryos for both Fox proteins failed to form somites 1-8, which indicates the importance of these proteins early on in somite development.