While the overall levels of STAT1 exhibited a slight increase at 16 and 20 h post-infection in cells infected with rIBV-ΔPL1pro-N compared to rIBV, the expression of p-STAT1 was notably elevated during these post-infection times in the rIBV-ΔPL1pro-N infected cells, peaking at 20 h post-infection (Fig. 5a). This evidence concerns the gene STAT1 and infection.