If you can’t defeat death, what if you could postpone it, or at least postpone the diseases commonly associated with getting old?

Many people, especially the ultra-wealthy in Silicon Valley, are investing money into companies trying to answer exactly those questions.

Amazon CEO Jeff Bezos and billionaire PayPal co-founder Peter Thiel have both invested in South San Francisco-based Unity Biotechnology, a company whose mission is to “extend human healthspan, the period in one’s life unburdened by the disease of aging.”