Fig. 2.

Transcription factors and signaling pathways implicated in the regionalization of gut endoderm. Schematic illustration (left) of a mouse embryo at E9 highlighting the position of the prospective stomach (red circle). Early gut regionalization (right) is mediated by key TFs and intercellular signals: SOX2 and HHEX are essential for foregut development, whereas CDX1 and CDX2 are required in the midgut and hindgut; signaling through the FGF and Wnt pathways posteriorizes gut endoderm and the regional attenuation of these signals promotes stomach development.