IFNG and infection: Interestingly, in comparison to the SARS-CoV-2 D614G- and Delta-inoculated cats, Omicron variant infection induced increased production of IFN-γ at days 7 and 14 pi (Fig 8C), higher level of RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted) at days 3 and 5 pi (Fig 8I).