Klotho - an aptly named protein
Named after the Greek Clotho, one of the three fates responsible for spinning the thread of human life.
A recent study of alpha and beta Klotho showed that beta Klotho is the primary receptor for FGF21, a protein that basically helps you burn calories faster.
Klotho is important because having a lot of FGF21 is associated with diabetes and some forms of fatty liver disease. So you can't just "take more FGF21" without something to balance it out.
If a way can be found to stimulate Klotho in the body (create more receptors) people with diabetes and fatty liver disease may get a boost. And those of us that are healthier may be able to increase our sensitivity FGF21, improving our healthspan and our ability to each chocolate chip cookies at the same time.