Consistent with the results from real-time RT-qPCR, protein levels of secreted IFN-β and IFN-λ3 (investigated using ELISA) were elevated at later times post-infection for cells co-infected with IAV DIPs and SARS-CoV-2 compared with cells infected with only SARS-CoV-2 (Figure 3B and 3C). The gene discussed is IFNB1; the disease is infection.