IFN-λ1 treatment alone, increased IFN-λ1 mRNA 70-fold at 6 h and 170-fold at 48 h post-treatment; while DENV-2 and IFN-λ1 treatment followed by infection increased IFN-λ1 levels somewhat less (65-fold and 55-fold for DENV-2 and 40-fold and 120-fold for IFN-λ1/DENV-2, at 6 h and 48 h post-infection, respectively). Here, IFNL1 is linked to infection.