Transcription factor that 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 (By similarity). 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; binds to and activates transcription from the G6PC1 promoter. Binds to the CYP3A4 promoter and activates its transcription in cooperation with CEBPA. Binds to the CYP3A7 promoter together with members of the CTF/NF-I family. Involved in regulation of neuronal-specific transcription. May be involved in regulation of spermatogenesis. Interacts with FOXA2. Expressed in erythroleukemia and hepatoma cell lines and in liver and pancreas. Not expressed in any other cell lines or tissues examined. Detected in prenatal liver nuclear extracts (12.4-27 weeks estimated gestational age). Not detected in postnatal liver samples. Hepatocyte nuclear factors entry