Six3/6 Products


The SIX proteins (sine oculis) are a family of homeodomain transcription factors that share a conserved DNA binding domain. Two of these family members Six3 and Six6 (also designated Optx2 and Six9) are required for the specification and proliferation of the eye field in vertebrates, and, therefore, are the vertebrate homologues most closely related to the Drosophila sine oculis protein, which has an essential role in controlling compound eye development. Six3 and Six6 expression largely overlap during development of specific tissues, such as retina, hypothalamus, and pituitary. The human Six6 gene maps to chromosome 14q22.3-q23. Haploinsufficiency of Six6 may cause several developmental disorders, including bilateral anophthalmia and pituitary anomalies. The gene encoding the human Six3 protein maps to chromosome 2p21-p22, a region associated with holoprosencephaly type 2 (HPE2). Deletion of Six3 may be associated with HPE2 disorder, a common, severe malformation of the brain that results from incomplete cleavage of the forebrain during early embryogenesis.


Entrez Human
Uniprot Human
Product By Gene ID 6496
Alternate Names
  • homeobox protein SIX3
  • sine oculis homeobox homolog 3 (Drosophila)
  • holoprosencephaly 2, alobar or semilobar
  • HPE2
  • Sine oculis homeobox homolog 3
  • SIX homeobox 3

PTMs for Six3/6

Learn more about PTMs related to Six3/6.


Bioinformatics Tool for Six3/6

Discover related pathways, diseases and genes to Six3/6. Need help? Read the Bioinformatics Tool Guide for instructions on using this tool.
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