This showed predictable spacing betweenthe motifs for ER, FOXA1 and GATA3, suggesting that all three proteins must be ableto associate with the adjacent pieces of DNA for them to co-operate and form anoestrogen-responsive complex that is capable of generating a stable DNA interaction.Specific inhibition of GATA3 in breast cancer cells pushes ER towards new DNA bindingsites that are demarcated by FOXA1 (52),suggesting that GATA3 might function as a rheostat, dictating possibleER–FOXA1 interactions. This evidence concerns the gene FOXA1 and breast carcinoma.