FFAR4 and infection: However, 2 days post-infection, the GPR120 KO mice that received 10-ODA or 18-HEPE administrations showed significant IFN-λ2,3 down-regulation in BALF and significantly higher virus titer in the lungs, compared with wild-type mice as well as IRF-7 KO mice, even though both mouse groups received similar 10-ODA or 18-HEPE treatments.