Abstract:  Fox (Forkhead box) protein family has 19 subfamilies. The members of these subfamilies are able to bind DNA, activate or inhibit the transcriptional activity of target gene, and can participate in cellular signal transduction, cell cycle regulation and metabolism regulation. Meanwhile, they play a key role in the development of organisms and their mature tissues and organs. Nowadays, the study of the function and molecular mechanism of Fox is gradually becoming a research hotspot in the fields of immunology, genetics, medicine and oncology. In this review, we summarized the nomenclature, the classification and the protein structure of the Fox and its functions on signal transduction pathways including the Hh, TGF-β/SMAD, MAPK, Wnt/β-catenin and IGF. The Fox family can regulate the development of many organs, such as the pharynx of Caenorhabditis elegans, the salivary gland of Drosophila melanogaster and the liver and eye of mammals. Fox is able to affect the cell cycle, and FoxA can regulate the metabolism by binding with CREB and GR. The copy number of Fox varies in different species and is subjected to strict evolutionary selection. The further research on the functions and molecular evolutionary mechanisms of the Fox genes will shed new insights into understanding the developmental mechanisms of organisms and the prevention and treatment of human diseases.

Key words: Fox, transcription factor, protein structure, molecular mechanism, signal transduction pathway