[card_zero]

So that's, what, a protein on the outside of the cell that lets the virus in, like its own particular catflap? And you're saying this portal is made of mucus, and mucus is what they want to repair, and therefore ... nope, can't piece the conclusion together, sorry. "Could infuence", as in?

[hirenj]

Catflap is a surprisingly apt analogy. In this case it is an endocytosis receptor, that selects cargo for uptake. Differs from virus to virus of course, but I could see changes in the sugars on these proteins altering behaviour. Mucus/mucins are basically proteins very heavily modified with sugars, so you have this common system that is adapted to do different things.

[card_zero]

(endocytosis, into-cell-doing.)