KRT18 and infection: A significant reduction of mAce2 expression was observed at 2 dpi in the lung of MA10- (P = 0.005) and USA-WA1/2020-infected (P = 0.007) K18-hACE2 mice and remained low over the course of infection (P ≤ 0.001 for MA10- and USA-WA1/2020-infected mice) (Fig. 8A).