#MolecularBiomarkerAnalysis

[elainaledoyen]

Cytokines​ are a broad and loose category of small ​proteins​ ​(5-20 kDa molecular weight) ​important in ​cell signaling​, particularly in the regulation of immune system responses to infection and inflammation. Cytokines​ are ​peptides​ and cannot cross the ​lipid bilayer​ of cells to enter the ​cytoplasm​. They communicate by signaling through cell surface receptors. Cytokines have been shown to be involved in autocrine, paracrine, and endocrine signaling pathways. ​Although secreted, cytokines are not considered to be hormones. ​There are several families of cytokines expressed in humans and other vertebrates and can act powerfully as individual molecular reagents although most often exert their influence combinatorially in multiple interactions c depending on the context in which they are expressed. ​The different types of cytokines, e.g., interferons, interleukins, lymphokines, chemokines, and tumor necrosis factors can act alone, work together, or work antagonistically in modulating a combinatorial response. Cytokines exert their influence on cells via cognate cell-surface receptors in either a paracrine fashion, i.e., by binding to receptors on other nearby cells, or in an autocrine mode, i.e., binding to receptors on the cell that secreted them.