Type III interferons (IFN) are the major player of mucosal immunity in the intestines of human and mouse.29 IFN lambda-1 (IFNL1) and IFNL3 were highly induced in human intestinal organoids upon viral infections.21,26 We first determined the sequences of horseshoe bat type III IFNs using RACE PCR. The gene discussed is IFNL3; the disease is viral infectious disease.