Bryan Johnson is a 45-year-old man - but he's managed to obtain the lungs of an 18-year-old youngster.
According to tests, the biotech entrepreneur has the heart of a 37-year-old, the skin of a 28-year-old, and the lung capacity and fitness of a late teenager.
But that isn't enough, as his aim is to eventually have all of his organs functioning as if they belonged to an 18-year-old, including his brain, liver, kidneys, teeth, skin, hair, penis and rectum.
