Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody .GATA-3, also known as endothelial transcription factor 3, is one of the six members of the GATA family of transcription factors taking part in the regulation of proliferation and differentiation of luminal epithelium of breast glands. GATA-3 is widely used as a marker for primary and metastatic breast carcinoma , transitional cell carcinoma, tumours of skin adnexa, yolk sac tumour.