Evaluation of: Brown A, Zhang H, Lopez P, Pardo CA, Gartner S:In vitro modeling of the HIV-macrophage reservoir. J. Leukoc. Biol. 80, 1127–1135 (2006). The main obstacle to viral eradication in HIV-infected patients is the presence of chronically infected latent reservoir cells, such as macrophages, and latently infected CD4⁺ T lymphocytes. New in vitro models might be useful to better understand the mechanisms involved in the formation of HIV reservoirs. In the above report, Brown and colleagues present evidence that macrophages represent a heterologous population of mononuclear phagocytes based on distinct profiles of viral replication, allowing in vitro modeling of the HIV-macrophage reservoir.