If they can learn more about how the human body ages, why it ages the way it does, why some people are able to live far longer than others, then perhaps we could apply these different facts in order to eventually prolong our lifespan.
If they can learn more about our genes and what causes us to be certain ways, they can use that to help create different medications to help mental health and physical health. They can let people who are prone to getting diseases, learn how to help prevent them.
