Everyone wants to know the secret to a long, healthy life. Now scientists have an idea just to what that secret is after blood samples from the longest-lived human in the world.

This study was published in the journal Genome Research.

Hendrikje van Andel-Schipper was 115 when she died in 2005 and she donated her body to science. Genetic analysis of her blood and tissue samples show that the key to longevity may be set by the cells ability to divide, according to Discover Magazine.

According to TIME everyone starts their lives with around 20,000 stem cells, only 1,300 of which are active.

Cells regenerate in our body every 25 to 50 weeks. When scientists performed the autopsy on Andel-Schipper she only had two active stem cells left. Their best guess is that the rest of them wore out and died.

Henne Holstege, the author of the study said, β€œAt first I could not believe that it was true. I thought it must be a technical error. It cannot be true that this person can still be alive with two stem cells.”

Holstege says that the results of this study definitely raise possibility of stem cells being the answer to our problems, like dying. We could possibly rejuvenate old, aging bodies with stem cells that were saved from earlier in our life.