FOXA1 and breast carcinoma: Based on the published interaction of GRHL2 with ER⍺, FOXA1, and GATA3 at enhancer elements of target genes [34–36, 57], we addressed to what extent the identified conserved GRHL2 binding sites in luminal breast cancer cells were flanked by putative binding sites for the ER⍺-mediated transcriptional complex.