The team has developed a strain of mice that produce a protein that glows whenever they make p16. "When they get older and have lots of senescent cells, they glow like crazy," says Sharpless. "When you expose them to gerontogens, they'll glow at a younger age than you expect."
The team members are using their mice to test potential gerontogens, and they've sent the animals to around 50 different labs that are doing the same. They're also working with a company called HealthSpan Diagnostics to create a version of their p16 test that could measure biological age in people.