Homeobox protein Hox-A13 is a protein that in humans is encoded by the HOXA13 gene.

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-genital syndrome, also known as hand-foot-uterus syndrome. Aberrant expression of HoxA13 gene products in the esophagus, provokes Barrett’s esophagus, a form of metaplasia that is a direct precursor to esophageal cancer.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.