Interestingly, there appears to be considerable regulation of IFN signaling at the receptor level: Type I IFN receptor expression has been shown to be induced in response to viral infection of host cells [42] and single nucleotide polymorphisms (SNPs) in the promoter region of IFNR- encoding genes IFNAR2 and IL10RB have been found to be associated with hepatitis B viral persistence [43]. Here, IFNAR2 is linked to hepatitis B virus infection.