In response to a viral challenge, cells can recognize an infection by detecting intracellular viral replication products (e.g. double-stranded RNA) via endogenous pattern recognition receptors (PRR) and this will stimulate the transcription and elaboration of type I interferons (IFN) (e.g. IFNα and IFNβ) (36), or in certain circumstances type III IFN (e.g. IFNλ) (37). This evidence concerns the gene IFNA1 and infection.