CCL2 and HIV-1 infection: Unlike what observed in uninfected histocultures (Figure 4A), a significant correlation was observed between the secreted levels of suPAR and those of CCL2/MCP-1 in supernatants of both R5 and X4 HIV-1 infected tissue blocks (Figure 4B and 4C), indicating that during HIV-1 infection a common mechanism of regulation or interdependency of the expression of suPAR and CCL2/MCP-1 occurred.