ESR1 and breast cancer: Although higher levels of ZFHX3-A mRNA in breast cancer cells are associated with better prognosis, such as smaller tumor size and reduced lymph node metastasis in breast cancer [17], ZFHX3 is transcriptionally upregulated by both the estrogen/ER and progesterone (Pg)/PR signaling pathways via the binding of ER and PR, respectively, to the ZFHX3 promoter [15,18,19].