Why shouldn’t our mitochondria want us to live long, prospering in good health? Why shouldn’t they — as symbiotic microbes turned cellular organelles with their own mini-genomes — carry genes that help ensure our healthful survival? After all, they ride around inside our cells, living on what we feed them, as they transform those elementals into the chemical fuel that powers us. In a variety of ways, they reach out and help keep our bodies whole and healthy as well. Many companies have sprung up around the idea of making medicine based on mitochondria’s role in health and disease, and one of them, CohBar, has chosen a unique way that avoids the common challenge of invading the cell’s interior to achieve therapeutic effects.