IFNB1 and infection: Noticeably, in addition to the previously reported mechanism, i.e. masking viral receptor ELR1 by the SU protein of EIAV [8,9], our results revealed that up-regulation of the soluble EIAV receptor and interferonβ (IFNβ) by activated Toll-like receptor 3 (TLR3) are also largely involved in the resistance to EIAVUK3 infection induced by EIAVFDDV13.