Hox genes:: a continuation of embryonic patterning?

The Hox genes encode a family of transcription factors that determine the identity of cells and tissues in the developing embryo. Recent findings have shown that their intricate pattern of embryonic expression continues into adulthood, where their original embryonic role is modified to meet specific regional needs, especially in tissues that undergo frequent renewal. Furthermore, it is now apparent that Hox expression can determine the identity of malignant cells in some tumour types.