HNF4A and breast cancer: The functions of these two ONRs in the context of breast cancer are not defined as yet, although HNF4α, a key transcriptional regulator of hepatocyte differentiation and function in liver, acts as a tumor suppressor in the diethylinitrosamine-induced rat model of liver carcinogenesis, and inhibits epithelial-mesenchymal transition (EMT) (69).