Samumed is finding it easy to raise huge amounts of cash because it believes it has invented medicines that can reverse aging. Its first drugs are targeted at specific organ systems. One aims to regrow hair in bald men. The same drug may also turn gray hair back to its original color, and a cosmetic version could erase wrinkles. A second drug seeks to regenerate cartilage in arthritic knees. Additional medicines in early human studies aim to repair degenerated discs in the spine, remove scarring in the lungs and treat cancer. After that Samumed will attempt to cure a leading cause of blindness and go after Alzheimer’s. The firm’s focus, disease by disease, symptom by symptom, is to make the cells of aging people regenerate as powerfully as those of a developing fetus. ... Hood, 49, had invented a cancer drug that got his previous company, Targegen, bought by Sanofi for $635 million. He has a distinct take on drug development: He thinks everybody takes too many shortcuts and insists on doing work himself that other companies outsource, including formulating drug chemistry, testing drugs in laboratory animals and running clinical trials. ... The target Hood and Kibar went after was obvious: a gene called Wnt, which stands for “wingless integration site,” because when you knock it out in fruit flies, they never grow wings. It’s a linchpin in a group of genes that control the growth of a developing fetus–whether you’re a fly or a person. Together these genes are known as the Wnt pathway. Trigger the right ones and you might revive old flesh. Some cancers do their dirty work by hijacking Wnt, and blocking it might stop tumors.

Paul attempted work on a memoir he had begun some years earlier, but he wasn’t confident that his life story was worth telling at all. He had expected a few consulting gigs to materialize, but each fell through, for one reason or another. A friend told Paul he had to be more entrepreneurial, to create his own opportunities. But Paul didn’t feel like an entrepreneur. He’d spent his life as a company man. ... Wanting to impress his fellow interns and bosses, Paul went to Ralph Lauren and spent his entire projected summer earnings on suits. ... as with any internship, the hope was that Paul would get as much as he gave—that he’d be learning something. Sally asked that Paul prepare to give a few presentations about his career to the other interns. That way, Paul would get a chance to hone his communication skills for an audience decades his junior.

The company’s mission: to build a Bell Labs of aging research. It hoped to extend the human life span by coming up with a breakthrough as important, and as useful to humanity, as the transistor has been. ... Google’s founders created an academic-biotech hybrid they call an R&D company to follow up on such clues, providing nearly unlimited funding to a group of top researchers. ... despite the hype around its launch—Time magazine asked, “Can Google Solve Death?”—Calico has remained a riddle, a super-secretive company that three years in hasn’t published anything of note, rebuffs journalists, and asks visiting scientists to sign nondisclosure agreements. ... Right now, there’s no proven test for a person’s “biological” age; finding one would be scientifically useful and possibly lucrative. ... For all these diseases, aging is the single biggest risk factor. An 80-year-old is 40 times as likely to die from cancer as someone middle-aged. The risk for Alzheimer’s rises by 600 times. But what if it were possible to postpone all these deaths by treating aging itself? … The experiment will generate millions of readings—for levels of growth hormones and glucose, among other things. Churchill wouldn’t say how much Calico is paying, but simply feeding that many mice could cost $3 million.