HMOX1 and infection: To investigate whether HO-1 induction exerted protective effects against DENV infection in vivo, 6-day-old ICR suckling mice were injected with DENV-2 intracerebrally and with HO-1 inducer CoPP (50 mg/kg) intraperitoneally at 1, 3, and 5 days post-infection (dpi).