Some studies revealed that no significant difference was detected in the expression of IFN-ε between healthy and acutely infected SIV rectal tissues or at 10, 14, or 28 days post-infection by immunofluorescence staining and quantitative real-time polymerase chain reaction (RT-PCR), indicating that acute SIV infection of the rectal tissue did not change the expression of IFN-ε mRNA (Demers et al., 2014). This evidence concerns the gene IFNE and infection.