GATA3 and breast carcinoma: Similarly, in the literature, GATA-3 has been reported to be superior to GCDFP-15 and mammaglobin in identifying breast carcinoma in metastatic tumors.16,17 However, GATA-3 has low specificity due to significant positivity in tumors like bladder carcinoma, and this should be kept in mind when attempting to identify the primary tumor in metastatic cases.17