Zinc-finger proteins contain DNA-binding domains and have a wide variety of functions, most of which encompass some form of transcriptional activation or repression. The majority of zinc-finger proteins contain a Krüppel-type DNA binding domain and a KRAB domain, which is thought to interact with KAP1, thereby recruiting histone modifying proteins. Zfy1 (zinc finger protein 1, Y linked), also known Zfy-1 is a 782 amino acid nuclear protein belonging to the Krüppel C2H2-type zinc-finger protein family and the ZFX/ZFY subfamily. Containing thirteen C2H2-type zinc fingers, Zfy1 is expressed in the genital ridge and adult testis and may be a probable transcription activator. The gene encoding Zfy1 maps to mouse chromosome Y.