KRT18 and infection: This is not desirable, as exposure of the nasal sinuses to high quantities of viral particles could cause serious adverse effects, as recently demonstrated in a study showing lethal SARS-CoV-2 neuroinvasion when K18-hACE2 mice were infected using intranasal dosing but not when mice were infected using aerosolization to more gradually initiate an infection with smaller droplets while producing a similar pulmonary viral load (24).