Next, we investigated the expression of bat IRF7 mRNA in Tadarida brasiliensis lung cells (TB 1 Lu) infected with RNA viruses such as Newcastle disease virus (NDV), avian influenza virus (AIV), vesicular stomatitis virus (VSV), and the double-stranded RNA (dsRNA) analogue poly (I:C) and demonstrated that these viral infections significantly upregulated the mRNA expression of bat IRF7. This evidence concerns the gene IRF7 and viral infectious disease.