Since the publication of The Hallmarks of Aging in 2013, aging research has exploded. The field now has more than 300,000 articles on the biological signals of the effect of time on the body. What would Marty McFly, the legendary character from the Back to the Future saga who traveled with his DeLorean time machine from the ‘80s to the ‘50s, think if he visited 2024 and saw laboratories experimenting with techniques to turn back the biological clocks of cells or increase the lifespan of rejuvenated mice?