A zinc finger transcription factor called GATA binding protein 3, or GATA3, is essential for regulating and promoting cell growth, development, and differentiation in a variety of tissues and cell kinds. The human GATA3 gene has been located at chromosome 10p15.3. The main sites of GATA3 expression are breast and urothelial carcinomas. In cases when breast or bladder tumors are suspected, anti-GATA3 can also aid in the diagnosis of unidentified primary carcinomas.