SULT1E1 and neoplasm: Recent studies have also demonstrated that HGSOC cells should be able to inactivate estrogens, as sulfotransferase 1E1 (SULT1E1), a key enzyme responsible for the sulfation of E1, E2, and dehydroepiandrosterone (DHEA), was detected in tumor sections from 137 HGSOC patients by immunohistochemical staining.