Silicon Valley billionaires are obsessed with 'reprogramming' their bodies for longevity. The first human trial suggests they may be onto something.

Jeff Bezos Mustafa Yalcin/Anadolu via Getty Images Tech billionaires are obsessed with "reprogramming" their bodies for longevity. Jeff Bezos, Peter Thiel, Yuri Milner, and Sam Altman have all invested in the rejuvenation strategy. The very first human attempt at cellular reprogramming is underway, and it looks like it's working. Getting old can be painful. Stick around long enough, and you're bound to weather some kind of age-related decline, like creaky joints, clogged arteries, or vision loss. Silicon Valley billionaires, including Jeff Bezos, Peter Thiel, Yuri Milner, and Sam Altman , who want to skip all that mess and reprogram their cells back to a more youthful state, have invested in startups working on the hottest trend in longevity science: cellular reprogramming . The technique has rejuvenated lots of mice and monkeys, but it had never been tried in humans — until this year.