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. TBZF (TRAF6-inhibitory zinc finger protein), also known as Zinc finger protein 675, is a 568 amino acid nuclear protein that contains one KRAB domain and fifteen C2H2-type zinc fingers. Through modulation of TRAF6 signaling activity and inhibition of RANK signaling, TBZF may play a role in osteoclast differentiation. TBZF is regulated during differentiation of human peripheral blood monocytes into osteoclasts and transfection of TBZF into RAW264.7 cells reduces RANK ligand-induced osteoclastogenesis.