['In this study, we characterized elvitegravir activity in the context of raltegravir resistance mutations.', 'Using site-directed mutagenesis, we generated recombinant integrase proteins and viruses harboring raltegravir resistance mutation to assess the biochemical and cellular activity of elvitegravir in the presence of such mutants.', 'Recombinant proteins were used in gel-based assays. Antiviral data were obtained with reporter viruses in a single-round infection using a luciferase-based assay.', 'Although main raltegravir resistance pathways involving mutations at integrase position 148 and 155 confer cross-resistance to elvitegravir, elvitegravir remains fully active against the Y143R mutant integrase and virus particles.'] Does elvitegravir overcome resistance to raltegravir induced by integrase mutation Y143?