KRT18 and COVID-19: Among these COVID-19 animal models, those that can be useful in studying the effect of S1P lyase inhibition on lung vasculature functionality, pathology, and inflammation are those that were found to reproduce the histopathological lung disease in a dose-dependent manner as was seen in humans, i.e., the hACE2-expressing mouse models (K18-hACE2 transgenic mouse model [104] and adenovirus hACE2 mouse model [105]), the Syrian hamster model [106], and the NHP models (cynomolgus macaques [107,108], rhesus macaques [109], African green monkeys [110], and baboons [111]).