This gene belongs to the regulatory factor X gene family, which encodes transcription factors that contain a highly-conserved winged helix DNA binding domain. The protein encoded by this gene is related to regulatory factors X1, X3, X4, and X5. This protein is transcription factor that acts as a key regulator of spermatogenesis. This protein can also bind to cis elements in the promoter of the IL-5 receptor alpha gene.