FOXO1 belongs to the forkhead family of transcription factors which are characterized by a distinct fork head domain. The specific function of this gene has not yet been determined; however, it may play a role in myogenic growth and differentiation.

Galili et al. (1993) isolated the chromosome 13 gene that is fused with PAX3. The rearrangement breakpoints occurred within an intron downstream of the paired box and homeodomain-encoding regions. Galili et al. (1993) identified the gene as a member of the forkhead domain family, which encodes transcription factors containing a conserved DNA-binding motif related to the Drosophila region-specific homeotic gene 'forkhead.' The distal half of the forkhead and the C-terminal region of the FKHR gene are involved in the chimeric transcript and fusion protein.