In the search for factors responsible for immune dysregulation, ephrin A1/A2 was identified as phosphorylated (activated) and upregulated in viral infected CRS ethmoid mucosal cells; ephrin A1/A2 is speculated to increase levels of inflammatory mediators and downregulate the protective PI3K-AkT-NFκβ pathway which activates antiviral immune responses. This evidence concerns the gene EFNA1 and congenital rubella syndrome.