KRT18 and infection: Clinical signs demonstrated that K18 hACE2 transgenic mice infected with rSARS-CoV-2 WT started losing body weight at 2 dpi and succumbed to infection by 6 dpi, and a comparable pattern of body weight loss was observed in animals infected with rSARS-CoV-2 Δ3a/Δ6 and rSARS-CoV-2 Δ3a/Δ7a (Fig. 3E).