In vertebrates, the genes encoding the class of transcription factors called homeobox genes are found in clusters named A, B, C, and D on four separate chromosomes. Expression of these proteins is spatially and temporally regulated during embryonic development. This gene is part of the A cluster on chromosome 7 and encodes a DNA-binding transcription factor which may regulate gene expression, morphogenesis, and differentiation. Expansion of a polyalanine tract in the encoded protein can cause hand-foot-uterus syndrome, also known as hand-foot-genital syndrome. [provided by RefSeq, Jul 2008],HOX1, HOX1J,Cell Biology & Developmental Biology,Epigenetics & Nuclear Signaling,Transcription Factors,HOXA13