Further, age-dependent differences, especially between young adult and aged infection groups animals, were observed in PC 1, which is composed of regulation of cilium movement-related genes such as DNAH11, DNAAF1, CFAP43, and CCDC40. These findings indicate that genes related to IFN responses are highly enriched in infected ferrets during the early stage of SARS-CoV-2 infection. Here, IFNA1 is linked to infection.