FOXH1 is a member of the Forkhead-box (FOX) family of transcription factors and is the human homolog of Xenopus forkhead activin signal transducer-1. FOXH1 plays an important role in mediating TGF-beta/activin signals throμgh its interaction with the SMAD2-SMAD4 complex. It is expressed primarily during early development and localizes in the cytoplasm until it forms a complex with the SMAD proteins at which time it translocates to the nucleus to positively or negatively affect gene expression.