– Sulfotransferase family cytosolic 2B member 1, also known as Sulfotransferase 2B1, ST2B1, Alcohol sulfotransferase, Hydroxysteroid sulfotransferase 2, SULT2B1 and HSST2, is a cytoplasm protein that belongs to the sulfotransferase 1 family. The human hydroxysteroid sulfotransferase (SULT) family is comprised of two subfamilies, SULT2A1 and SULT2B1. SULT2B1 is expressed highly in placenta, prostate and trachea. A lesser expression of SULT1B1 was observed in the small intestine and lung. SULT2B1 catalyzes the sulfate conjugation of many hormones, neurotransmitters, drugs and xenobiotic compounds. Sulfonation increases the water solubility of most compounds, and therefore their renal excretion, but it can also result in bioactivation to form active metabolites. SULT2B1 sulfates hydroxysteroids like DHEA. Isoform 1 preferentially sulfonates cholesterol. The two SULT2B1 isoforms, SULT2B1a and SULT2B1b, are encoded by a single gene as a result of alternative transcription initiation and alternative splicing. SULT2B1b catalyzes the sulfonation of 3beta-hydroxysteroid hormones and cholesterol, whereas SULT2B1a preferentially catalyzes pregnenolone sulfonation.