Mice, by virtue of being vertebrates, and more specifically mammals, share much biology with us - from biochemistry, to cellular functions, to macro structures. There's a reasonable chance things that affect their bodies will affect ours as well.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4594046/
More than 95% of successful animal studies fail to progress further from human trials.
There's obviously a great need for doing these tests in a different fashion.