Engrailed homeobox transcription factors as potential markers and targets in cancer

► Engrailed (En) is a member of the homeobox gene family. ► En encodes a transcription factor that is essential during early development. ► The only known site of normal adult EN protein expression is in the nervous system. ► Over-expression of EN has been linked to breast, prostate and ovarian cancers. ► EN2 may prove useful as a biomarker, notably in the urine of prostate cancer patients.