ESR1 and neoplasm: When these results were compared with IHC stains of FOXA1 and GATA3 on the same cases, there was significant association of positive FOXA1 and GATA3 cases with cases that were also positive for ER (Figure S1 in Additional file 2), suggesting an up-regulation of the ER pathway, possibly driven by FOXA1 and GATA3, may be an important early event in the majority of early neoplasias.