IFNA1 and viral infectious disease: To evaluate whether type I and/or III IFN protect primary human IECs from viral infection, organoid cultures were treated with 8 ng/mL of type I IFN (IFN-β) (equivalent 2,000 RU/mL, see Materials and Methods) or 300 ng/mL of type III IFN (IFN-λ1−3) prior to exposure to MRV.