CX3CL1 and HIV infectious disease: In the CNS, sCX3CL1 dysregulation in the brain was observed during HIV infection [83]; CX3CL1 was up-regulated in the brain tissue and cerebrospinal fluid of HAND patients and released in response to proinflammatory stimuli, mainly in the neurons, and in co-cultures of astrocytes and HIV-infected Mφs [82,84].