FOXP3 and breast cancer: Other transcription factors have been identified as negative regulators of ERBB2 expression in breast cancer (for a review, see [37]): e.g., PEA3, an Ets DNA-binding protein that targets a DNA motif in the ERBB2 gene promoter [38]; FOXP3, an X-linked breast cancer tumor suppressor which represses the transcription of the ERBB2 gene by interacting with forkhead DNA-binding motifs in the promoter [39]; the zinc-finger transcription factor GATA4, part of a negative feedback regulatory loop with the ERBB2 gene [40].