We analyzed the existing evidence for some of the most relevant cytokines released into the blood upon infection in three categories: antiviral (IFNγ, CXCL1, CXCL10), inflammatory (IL-1β, IL-6, IL-10, IL-2, IL-4, IL-7, IL-8, and TNFα), and monocyte chemoattractant proteins (MCP1, also called CCL2, and MCP3, also called CCL7), as well as MIP-1α, also called CCL3, GM-CSF, and G-SCF. This evidence concerns the gene IL4 and infection.