The Division of Acquired Immunodeficiency Syndrome of the National Institute of Allergy and Infectious Diseases, in collaboration with the Southern Research Institute and NCBI, maintains a comprehensive HIV Protein-Interaction Database of documented interactions between HIV-1 proteins, host cell proteins, other HIV-1 proteins or proteins from disease organisms associated with HIV or AIDS (56). Summaries, including protein RefSeq accession numbers, Entrez Gene IDs, lists of interacting amino acids, brief descriptions of interactions, keywords and PubMed IDs for supporting journal articles are presented at www.ncbi.nlm.nih.gov/RefSeq/HIVInteractions/. All protein–protein interactions documented in the HIV Protein Interaction Database are listed in Entrez Gene reports in the HIV-1 protein interactions section.