The Six proteins (sine oculis) are a family of homeodomain transcription factors that share a conserved DNA binding domain. Six2, Six4 (AREC3) and Six5 bind to the same DNA sequence, indicating that they may regulate the same target genes. Six1 overexpression has been shown to abrogate the G2 cell cycle checkpoint.Six2 is highly expressed in fetal tissues but expression is limited in adult tissues.
