Transcription factor which plays a key role in limb development. Positively regulates FGF8 expression in the apical ectodermal ridge (AER) and contributes to limb outgrowth in embryos (By similarity). The 9aaTAD motif is a transactivation domain present in a large number of yeast and animal transcription factors. Belongs to the Sp1 C2H2-type zinc-finger protein family.