Harvard scientist David Sinclair reveals breakthrough human trials using gene therapy to reverse aging. His lab's OSK gene therapy restores vision in glaucoma patients and reverses cellular aging in mice by 75%, potentially opening the door to treating age-related diseases like Alzheimer's and arthritis through epigenetic reprogramming. Three genes called OSK can safely reprogram cells to behave like younger versions by reinstalling their youthful epigenetic instructions without causing cancer or stem cell transformation.