TY - BOOK AU - Kirchhoff,F. AU - Carl,S. AU - Daniels,R.S. AU - Douglas,N. AU - Easterbrook,P.J. AU - Greenough,T.C. AU - Sullivan,J.L. AU - Troop,M. AU - Weber,J. TI - Sequence variations in human immunodeficiency virus type 1 Nef are associated with different stages of disease ER -