GATA3 and neoplasm: Among the genes showing the top-ranked fold changes in expression between luminal tumor and normal breast tissue, we found an interesting candidate, GATA3, which is a member of the GATA family of transcription factors that is essential to the establishment and maintenance of luminal epithelial cell identity during mammary gland development (30) as well as a master regulator of T cell and innate lymphoid cell development (31).