Given that viral infection and Spike protein could induce the expression of type I and II interferons (IFNs), we treated Caco-2 monolayer cultures with recombinant human IFN-α (IFN-α 2a), IFN-β, IFN-γ, or IFN-λ proteins for 24 h and quantified LSR mRNA levels using RT-qPCR. Here, IFNA1 is linked to viral infectious disease.