Ninety-nine years ago, Peyton Rous discovered that avian sarcomas could be transmitted by a filterable agent. Although one of the first discovered viruses was a retrovirus, this family still poses some of the most important and most intractable problems in medicine in the form of HIV and the AIDS epidemic.

In the intervening years, retroviruses have led to many discoveries of fundamental importance in medicine, such as oncogenes, and to essential laboratory tools such as reverse transcriptase and lentiviral vectors. The therapeutic use of retroviruses as gene delivery vectors, although still in its infancy, holds great promise for certain genetic disorders, such as immunodeficiency diseases of childhood. Retroviruses, therefore, still occupy a central place in biology and medicine.

This book is designed as a succinct, state-of-the-art summary of the biology not only of retroviruses but also other retroelements. The 16 chapters follow a logical sequence from evolutionary biology through molecular virology, transmission and epidemiology, pathogenesis and gene delivery vectors, to animal and human retroviruses. There are timely chapters on the exciting recent advances in retroviral entry and retroviral restriction factors.

The volume is chiefly written by, and directed at molecular virologists. While it is impractical to include all aspects of the medicine and biology of this extraordinary diverse range of agents, there is a notable lack of emphasis on immunology in the book. There is an excellent chapter on 'Molecular vaccines and correlates of protection', but while this gives a full account of the diverse tactics and vectors that have been, and are being developed, the correlates of protection are not presented or analysed in detail. For example, "At the intellectual level, one great difficulty is that the so-called 'correlates of immune protection' against HIV or SIV are not known." (p. 329). Obstacles to the development of vaccines against HIV are discussed, and listed in Table 12.4, which is closely followed by 'reasons for optimism that an HIV vaccine is possible' in Table 12.5.

Since the classic series on RNA tumour viruses from the Cold Spring Harbor Press in the 1980s, there have been few single monographs that provide a succinct and wide-ranging summary of the biology of retroviruses. This volume makes a more comprehensive, convenient and satisfying reference work on these agents than can be found on the web: the book still has a place in the laboratory.