Transcription factor that is involved in embryonic development, establishment of tissue-specific gene expression and regulation of gene expression in differentiated tissues. Is thought to act as a 'pioneer' factor opening the compacted chromatin for other proteins through interactions with nucleosomal core histones and thereby replacing linker histones at target enhancer and/or promoter sites. Binds DNA with the consensus sequence 5'-[AC]A[AT]T[AG]TT[GT][AG][CT]T[CT]-3' (By similarity). Proposed to play a role in translating the epigenetic signatures into cell type-specific enhancer-driven transcriptional programs. Involved in the development of multiple endoderm-derived organ systems such as the liver, pancreas, lungs and prostate; FOXA1 and FOXA2 seem to have at least in part redundant roles. Plays a role in prostate morphogenesis and epithelial cell differentiation. FOXA1 and FOXA2 are essential for hepatic specification. FOXA1 and FOXA2 are required for morphogenesis and cell differentiation during formation of the lung. FOXA1 and FOXA2 are involved in bile duct formation; they positively regulate the binding of glucocorticoid receptor/NR3C1 to the IL6 promoter. FOXA1 and FOXA2 regulate multiple phases of midbrain dopaminergic neuron development; they regulate expression of NEUROG2 at the beginning of mDA neurogenesis and of NR4A2 and EN1 in immature mDA neurons. Modulates the transcriptional activity of nuclear hormone receptors. Is involved in ESR1-mediated transcription. Inhibits NKX2-1-mediated transcription from the SFTPC promoter in lung epithel independently from DNA-binding. Involved in regulation of apoptosis. Involved in cell cycle regulation. Originally described as a transcription activator for a number of liver genes such as AFP, albumin, tyrosine aminotransferase, PEPCK, etc. Interacts with the cis-acting regulatory regions of these genes. Involved in glucose homeostasis; activates the GCG promoter. Binds DNA as a monomer. Interacts with FOXA2. Interacts with NKX2-1. Interacts with HDAC7. Interacts with the histone H3-H4 heterodimer. Associates with nucleosomes containing histone H2A. Interacts with AR. Interacts with NR0B2 (By similarity). Restricted mainly to endoderm-derived tissues (lung, liver, stomach, and small intestine). Expressed in the prostate. Most abundant in midgestation embryos (day 9.5). In embryonic lung expressed at 12 dpc and 18 dpc with highest levels in proximal airways and lowest levels in the distal lung. The prostate shows a severely altered ductal pattern that resembles primitive epithelial cords surrounded by thick stromal layers; no differentiated or mature luminal epithelial cells are found. Dehydration and electrolyte imbalance, development of mild nephrogenic diabetes insipidus. Severe hypoglycemia due to at least in part diminished expression of GCG. Mice deficient for Fox1a and deficient for Foxa2 in the endoderm from 8.5 dpc onwards do not show hepatic bud formation. Mice deficient for Fox1a and deficient for Foxa2 in the midbrain from 10.5 dpc onwards show almost complete loss of mDA neurons. Mice deficient for Fox1a and deficient for Foxa2 in the embryonic liver show hyperplasia of the biliary tree due to at least in part activation of IL-6 expression, a proliferative signal for cholangiocytes.