In the long run, using mice to test human medicines will result in selection pressure for humans whose physiology more and more closely resembles mice.

(not mice), but Fancy Rats are extremely susceptible to tumors. It sucks. More rats I've owned have died of either cancer or respiratory illnesses than old age.

Bonus shot of my boy Finn:

Cancer isn’t one thing.

Just like with antibiotics. When Penicilin was originally tested, they happened to test it on just the right animals. One kind of standard lab animals would have just died from that stuff.

I mean, there are like dozens of different types of cancers, so we probably have missed some of them.

Or it was too cheap to duplicate so there was no profit in it…

Or it worked too well on mice and stopped regular cells from dividing.

There are preventative measures but they’re all based on the rich not poisoning everyone for profit.

The crazy thing is we actually do have things that work in humans but not in mice. Mice are omnivores and are very different in terms of optimal energy state. They tend to run in glucose more easily than on fat and their whole biology is built to be small and fast, with short life spans.

Checking how DNA repair works in an animal which lives for maybe 2 years is great for understanding DNA repair in short lived organisms, but we have tk repair damage for 50 times as long. It is just so much more complex and requires such different tools when you switch from maybe 2 years to maybe 80 years, it really isn't sane to assume it will all carry over.

Now for an accute toxin, say tobacco, sure, some things work just fine. There is not a huge difference between humans and mice when subjected to cyanide or arsenic. Being crushed by a falling piano is going to kill both of us. But a chronic poison? That will take decades to kill? That is very different. We can shed cells in a different way to how they can. We have more mass to store things. We have more energy storage. We have bigger kidneys with more opportunities for filtering. We are different.

When we enter ketosis we have some fairly significant cancer responses. When we maintain fasting for 5+ days we have a fairly large bump in autophagy, a state where the body kills off and recycles damaged cells. This state can cause some types of cancer to be more obvious to our immune systems and allow the tumor to be attacked. In some cases otherwise inoperable tumors can be removed after shrinking them through fasting. This does not replicate in mice. So yes, some treatments (not cures because that doesn't really apply) do work in humans and not in mice.

They're cooking up human organoids just for that.

Also who is out there making sure all of these incredible discoveries are accessible to mice more broadly, outside the labs?

This IS happening, right?

Otoh, mice have never been healthier.