Sulfotransferase enzymes catalyze the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds.Particularly SULT1A1 (Sulfotransferase family, cytosolic, 1A, phenol-preferring, member 1), a member of the sulfotransferase 1 subfamily, which is a major pathway for drug metabolism in humans. Statistically significant associations were observed between the SULT1A1 genotype (Arg213His) and age, obesity and certain neoplasias (mammary, pulmonary, esophageal and urothelial cancer). Furthermore, the polymorphism of the SULT1A1 may be closely associated with breast cancer.