Estrogen sulfotransferase, also known as Sulfotransferase, estrogen-preferring, Sulfotransferase 1E1, SULT1E1 and ST1E1, is a cytoplasm enzyme which belongs to the sulfotransferase 1 family. Sulfotransferase enzymes catalyze the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds. These cytosolic enzymes are different in their tissue distributions and substrate specificities. SULT1E1 may control the level of the estrogen receptor by sulfurylating free estradiol. SULT1E1 maximally sulfates beta-estradiol and estrone at concentrations of 20 nM. SULT1E1 also sulfates dehydroepiandrosterone, pregnenolone, ethinylestradiol, equalenin, diethylstilbesterol and 1-naphthol, at significantly higher concentrations; however, cortisol, testosterone and dopamine are not sulfated. SULT1E1 is a key enzyme in estrogen homeostasis. It plays a central role in the prevention and development of human disease.