Retrovirology is an open access, online journal that publishes stringently peer-reviewed, high-impact articles on host-pathogen interactions, fundamental mechanisms of replication, immune defenses, animal models, and clinical science relating to retroviruses. Retroviruses are pleiotropically found in animals. Well-described examples include avian, murine and primate retroviruses. Two human retroviruses are especially important pathogens. These are the human immunodeficiency virus, HIV, and the human T-cell leukemia virus, HTLV. HIV causes AIDS while HTLV-1 is the etiological agent for adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. Retrovirology aims to cover comprehensively all aspects of human and animal retrovirus research.