Zfx and Zfy are transcription factors implicated in mammalian sex determination. This region is found N terminal to multiple copies of a C2H2 Zinc finger (Pfam:PF00096). This region has been shown to activate transcription when fused to a GAL4 DNA binding domain [1].

1: Mouse Zfx protein is similar to Zfy-2: each contains an acidic activating domain and 13 zinc fingers. Mardon G, Luoh SW, Simpson EM, Gill G, Brown LG, Page DC; Mol Cell Biol 1990;10:681-688. PMID:2105457