May act as a transcriptional regulator involved in the differentiation of young endothelium. Altered differentiation results in incompetence for pigments synthesis and the lack of condensed tannins in the seed coat (PubMed:21477081). Plays a role in the regulatory network controlling flavonoid accumulation in endothelium cells during seed development (PubMed:21477081). Can form homodimers. Interacts with MYB75, TT2 and TT16. Restricted to the endothelium, the innermost cell layer of the seed coat and detected to a lesser extent in the other cell layers of the testa. Developing ovules and young seeds. Lack of flavanoid pigment accumulation in the seed coat endothelium (transparent testa phenotype). Belongs to the WIP C2H2-type zinc-finger protein family.