Since the discovery of human immunodeficiency virus (HIV), the world of retrovirology has gained a degree of prominence that is the envy of most other fields of virology. The Retroviridae family is truly enormous, both in the scope of host range and in its molecular and genomic diversity. The editors have gathered together an extensive array of experts that present their respective topics clearly, with a plentiful supportive data. Each chapter concludes with an extensive and up-to-date bibliography.