HNF4A is a nuclear transcription factor which binds DNA as a homodimer. This protein controls the expression of several genes, including hepatocyte nuclear factor 1 alpha, a transcription factor which regulates the expression of several hepatic genes. This protein may play a role in development of the liver, kidney, and intestines. Mutations in this protein have been associated with monogenic autosomal dominant non-insulin-dependent diabetes mellitus type I.