Color reproduction on the Web. Overview of two-dimensional gel electrophoresis (2D-GE) showing protein profiles in control, HIV-1+, HCV+ and HIV-1+/HCV+ peripheral blood mononuclear cells (PBMCs). The red squares in control samples represent the downregulated proteins while in infected samples represent the up-regulated proteins. The consistently identified proteins as common spots on the 2D gels among all the four conditions are indicated with capital letters. All experiments were performed in triplicate. Representative 2D gel (from which spots were selected) images are provided here.