That's on the inside, though. The ISS has to mitigate mold as well.

https://newspaceeconomy.ca/2023/03/29/mold-in-space-the-hidd... has a picture of a wall panel covered in the stuff after astronauts hung damp workout clothes out to dry.

Well it was made out of plywood. Unless they made the wood poisonous to all life, it is also food. And humans basically exhale the rest of what fungi need to thrive.

Space is not all that inhospitable to life. There are strong theories that after major cataclysms on earth, rocks in space with life attached then reseeded earth when they came back down.

I was sorta hoping that radiation would mutate the Mir Fungus into something really catastrophic that would survive Mir's re-entry and then more or less destroy the world. Or at least that someone would have made a really nutso film based on such an idea.