In vitro selection of resistant HIV from wild-type in the presence of amprenavir, lopinavir, nelfinavir, or darunavir (TMC114) in sequential passage experiments. Each passage represents 3–4 days with passage 75 representing a total of 260 days. Enlarged symbols indicate genotypes of viruses selected at defined times and list all genotypic changes from the original HIV-1 LAI strain. Curves are normalized and starting concentrations were 10, 20, 100 and 100 nM for darunavir (TMC114), lopinavir, amprenavir and nelfinavir respectively (reproduced with permission51).