Transcription factor; binds and activates the promoter for the HNF1-alpha gene. Seems to have a lower DNA binding activity than HNF4-alpha and is a weaker transactivator than the alpha isoform. Homodimerization is required for HNF4-alpha to bind to its recognition site. Expressed in liver, kidney, stomach, intestine, lung, ovary, and testis. Not expressed in fat, muscle and brain. Maternal protein which is distributed within an animal-to-vegetal gradient in the embryo. Present from the egg stage onward and throughout the entire development. Belongs to the nuclear hormone receptor family. NR2 subfamily.