Leónization (named for Ponce de León, a Renaissance explorer who sought the Fountain of Youth) is a genetic anti-aging treatment that rejuvenates the body at the cellular level.
A potent combination of nanite gene therapy and cellular repair, it restores the individual to the approximate physique and youth of a young adult. It is not known if there are any negative side effects from long term use and repeated treatments. The technique also is prohibitively expensive, with a cost in the millions of nuyen, and thus remains only within the grasp of the rich and powerful.
To participate, the individual must stay within a nutrient bath for at least four months, with semi-annual "touch-up" sessions for the next few years. It is rumored that after a certain number of treatments, the subject's cells start to spontaneously degenerate and break down, causing death within hours.