IFNA1 and infection: In the hDPP4-KI mouse model, infection with MERS-CoV-MA-WT moderately increased IFN-β levels at 4 and 6 dpi in contrast to almost undetectable levels observed in the absence of protein 4b or in the presence of cytoplasmic 4b-mNLS, suggesting that 4b nuclear location was required to induce IFN-ß production.