The major mechanism responsible for estrogen-induced cholestasis is the activation of ERa receptor with consequent transcriptional repression of basolateral uptake transporters for BAs such as Slc10a1 (Ntcp), and BA synthetic enzymes such as Cyp7a1 and Cyp8a1 (Geier et al., 2003, 2007; Yamamoto et al., 2006). This evidence concerns the gene PTGIS and cholestasis.