CD4 and HIV infectious disease: It has been suggested that a cytokine storm, with elevated levels of interferon (IFN)-α, IFN-γ, interleukin (IL)-15, IFN-γ-inducible protein-10 (IP-10), TNF-α, monocyte chemotactic protein-1 (MCP-1), IL-6, and IL-18, is occurring during acute HIV infection [83] and may contribute to CD4+ T cell apoptosis [84].