Finally, a decrease in peripheral blood pDCs has been shown to be associated with HIV infection, and previous studies have indicated that HIV-mediated pDC activation leads to the upregulation of CCR7 and the production of CCL2, CCL3, and CCL4 [23], [24], [26], which may lead to migration of pDCs to various tissue compartments. This evidence concerns the gene CCL2 and HIV infectious disease.