PRDM9 and breast neoplasm: It is possible that BRCA1 binds to the promoter of GATA3 to directly activate the transcription of GATA3. In addition, since histone methyltransferase EZH2 is overexpressed in BRCA1-deficient breast tumor cells 67, and EZH2 binds to Gata3 promoter repressing its transcription 68, 69, it is also possible that BRCA1 prevents EZH2-mediated H3K27 trimethylation at the GATA3 locus to maintain GATA3 transcription.