Forkhead box (FOX) proteins are a ubiquitously expressed family of transcription factors that regulate the development and differentiation of a wide range of tissues in animals. The FOXP subfamily members are the only known FOX proteins capable of forming domain-swapped forkhead domain (FHD) dimers. The change in dynamics of the hinge-loop region of FOXP2 alters the energetics and mechanism of DNA binding highlighting the critical role of hinge loop mutations in regulating DNA binding characteristics of the FOX proteins. FOXP2 is a transcription factor expressed in multiple tissues during embryonic development. FOXP2 regulates transcription by binding to DNA at its DNA binding domain, the forkhead domain (FHD) through the recognition helix. FOXP2 as a novel suppressor and prognostic marker of breast cancer metastasis. FOXP2 encodes a transcription factor involved in speech and language acquisition. Mutations of the FOXP2 gene cause a severe speech and language disorder, providing a molecular window into the neurobiology of language.