Subsequent immunostaining for viral protein expression and histopathology analysis showed that viral translation was observed in several areas of the alveolar epithelium of the IFN-treated infected lung xenografts at 2 dpi, but neither viral protein nor any histopathological change was detected in xenografts at 4 and 6 dpi (Figure 5C), indicating that there likely was an initial cycle of replication before the infection was controlled by the IFN-α antiviral activity. This evidence concerns the gene IFNA1 and infection.