One of the more interesting findings regarding these mice was the heavy viral infection in the brain with increased inflammatory cytokines (CXCL-1, CXCL-10, IL-6, IL-1beta, etc.)(Fig. 2), postulated to be a major factor in the aspiration pneumonia observed in K18-hACE2 Tg mice and occasionally in infected patients as well [66]. Here, KRT18 is linked to viral infectious disease.