Color reproduction on the Web. Proposed model highlighting specific protein signatures triggered by HIV-1 (A), HCV (B) and HIV-1/HCV (C) in peripheral blood mononuclear cells. ROS, reactive oxygen species; RS, reactive substances; GST, Glutathione S-transferase. Arrows up indicate up-regulated proteins and arrows down indicate down-regulated proteins. Underlined proteins are proteins unique to each of the conditions (HIV-1, HCV and HIV-1/HCV samples).