[EN-2: a multi-functional transcription factor of vertebrates]

Homeobox protein engrailed-2 (EN-2), is a subtype of the homeoprotein transcription factors of EN family. It can be transported between cells in culture by unconventional secretion and internalization mechanisms. When internalized, it can activate the transcription or translation. EN-2 had been considered to be an important transcriptional factor during the embryonic development , it involved in the regulation of anteroposterior polarity. In recent years, much more functions of EN-2 are revealed. It controls synaptic choice as well as axon projections; and there are some relationships between EN-2 and Parkinson's disease. Furthermore, EN-2 is thought to be a candidate oncogene in human breast cancer and a candidate gene of Autism Spectrum Disorder. The structure, distribution, function and regulation of EN-2 as well as the relationships between EN-2 and some diseases are reviewed in the present article.