In endometrial cancer cell line Ishikawa SULT1E1 is induced by steroid drug tibolone via progesterone receptor (Falany and Falany, 2006), while in liver it is repressed by xenobiotic activators of the pregnane X receptor and aryl hydrocarbon receptor peroxisome proliferator, and activated via peroxisome proliferator activated receptor α and the liver X receptor (Duanmu et al., 2007). Here, SULT1E1 is linked to endometrial cancer.