IFNAR1 and infection: Serum ALT elevations were comparable in the two types of mice at days 7 and 14 p.i. (Fig 6B), but HAV RNA levels in both liver and feces were significantly greater in the Ifnlr1-/-Ifnar1-/- mice than Ifnar1-/- mice on day 14 post-infection (Fig 6C and 6D).