GATA3, a member of the GATA zinc finger transcription factor family, and its dysregulation has been implicated in various types of malignancies. GATA3 serves as an oncogene in GC development. The GATA3 transcription factor is one of the most frequently mutated genes in breast cancer. Overexpression of GATA3 in keratinocytes reversed this effect and significantly upregulated filaggrin and, furthermore, filaggrin-2 mRNA expression. GATA3 is involved in the regulation of filaggrin and filaggrin-2 expression during inflammatory conditions in the skin. GATA3 is a transcription factor used clinically as a marker of breast or urothelial differentiation.