The article discusses the unified nomenclature for the winged helix/forkhead (WH/FOX) transcription factors, which are characterized by a 100-amino-acid DNA-binding domain. Over the past 9 years, more than 100 members of this gene family have been identified across various species. The rapid accumulation of sequences has led to multiple naming systems, making it difficult to follow the literature. At the first International Meeting on Forkhead/Winged Helix Proteins in 1998, a proposal was developed to standardize the nomenclature, adopting "Fox" as the unified symbol for chordate WH/FOX transcription factors. A nomenclature committee was elected to implement this proposal, and it has been endorsed by over 20 scientists and gene nomenclature committees. The Fox proteins are divided into 15 subclasses based on phylogenetic analysis, with each subclass designated by a letter and each protein within a subclass given an Arabic numeral. The nomenclature system aims to assign consistent names to orthologous proteins from different species. The article also provides guidelines for naming new sequences and encourages investigators to submit sequences to the Fox Nomenclature Committee for proper assignment.The article discusses the unified nomenclature for the winged helix/forkhead (WH/FOX) transcription factors, which are characterized by a 100-amino-acid DNA-binding domain. Over the past 9 years, more than 100 members of this gene family have been identified across various species. The rapid accumulation of sequences has led to multiple naming systems, making it difficult to follow the literature. At the first International Meeting on Forkhead/Winged Helix Proteins in 1998, a proposal was developed to standardize the nomenclature, adopting "Fox" as the unified symbol for chordate WH/FOX transcription factors. A nomenclature committee was elected to implement this proposal, and it has been endorsed by over 20 scientists and gene nomenclature committees. The Fox proteins are divided into 15 subclasses based on phylogenetic analysis, with each subclass designated by a letter and each protein within a subclass given an Arabic numeral. The nomenclature system aims to assign consistent names to orthologous proteins from different species. The article also provides guidelines for naming new sequences and encourages investigators to submit sequences to the Fox Nomenclature Committee for proper assignment.