Interferons (IFNs) were first described in 1957 by Issacs and Lindenmann as substances that restrict viral replication (Isaacs and Lindernmann 1957). In mid-1960, Wheelock reported that human leukocytes stimulated with phytohemagglutinin expressed IFN-like inhibitors (Wheelock 1965). However, these IFN-like substances had less resistance to heat and acid than the interferons described previously. In the 1970s, these substances were further characterized based on the inducing properties and cell-type expression patterns, and first named Immune IFN, then later Type II IFN. This nomenclature was originally a subject of some debate as the Type II IFN was thought to be physicochemically and also biologically different from Type I IFNs (IFN-α, IFN-β, IFN-ω, and IFN-τ) (Billiau 2009). In 1980, a panel of experts acknowledged the differences between Type I and Type II IFNs, and gave the Type II IFN the...