Bowhead whales use a protein called CIRBP to meld broken DNA back together in such an efficient fashion that these guys live to be over 200 years old. This goes against what one would expect from such a large animal with so much DNA; we would expect more mutations and a reduced life span (Peto's paradox). While humans also have CIRBP, ours is much less efficient at repairing DNA and preventing mutations. Scientists took whale CIRBP and put it in human cells, and found that it worked to reduce DNA mutations in our cells, just like it does in whales. This has big implications for cancer research. Whales are cool.

https://www.nature.com/articles/s41586-025-09694-5