The Bioethics Thesaurus is a controlled subject heading vocabulary developed at the Kennedy Institute of Ethics, Georgetown University, specifically for indexing the literature of the cross-disciplinary field of bioethics. It was used to index BIOETHICSLINE from 1975-2000. The first published edition of the Bioethics Thesaurus appeared in the 1975 edition of Bibliography of Bioethics, containing 475 Keyword Descriptors. In 1999 a print edition of the Bioethics Thesaurus was published that contained 715 Keyword Descriptors. It has been updated extensively, particularly to include new genetics terms for the GenETHX database, and new Islamic ethics terms for the Islamic Medical and Scientific Ethics database. It now contains more than 745 keywords. Bioethics is a branch of applied ethics that studies the value implications of practices and developments in the life sciences, health care, medicine, and related areas of research.