Institute for Immunology and Genetics View Institution's Website 1 article published in JoVE Immunology and Infection Prediction of HIV-1 Coreceptor Usage (Tropism) by Sequence Analysis using a Genotypic Approach Saleta Sierra1, Rolf Kaiser1, Nadine Lübke1, Alexander Thielen2, Eugen Schuelter1, Eva Heger1, Martin Däumer3, Stefan Reuter4, Stefan Esser5, Gerd Fätkenheuer6, Herbert Pfister1, Mark Oette7, Thomas Lengauer2 1Institute of Virology, University of Cologne, 2Max Planck Institute for Informatics, 3Institute for Immune genetics, 4Department of Gastroenterology, Hepatology and Infectiology, University of Duesseldorf, 5Department of Dermatology, University of Essen, 6Department of Internal Medicine, University of Cologne, 7Augustinerinnen Hospital The prediction of the coreceptor usage of HIV-1 is required for the administration of a new class of antiretroviral drugs, i.e. coreceptor antagonists. It can be performed by sequence analysis of the env gene and subsequent interpretation through an internet based interpretation system (geno2pheno[coreceptor]).