Not detected in any adult tissues tested. Expressed in headfold stage embryos in the notochord, the anterior neuroectoderm, and a few cells of the definite endoderm. This expression becomes restricted to the anteriormost portions of the invaginating foregut and the developing midbrain. From day 11.5 of gestation onward, FOXD4 transcripts are restricted to the midbrain and become progressively localized to the red nuclei as the sole site of expression. Contains two potential transactivation domains A and B.