Epigenome
The system of chemical markers and histone proteins that package DNA, controlling which genes are turned on or off in different cell types. Loss of information here is hypothesized to be the cause of aging.
Videos Mentioning Epigenome

The Biology of Slowing & Reversing Aging | Dr. David Sinclair
Andrew Huberman
The system that controls which genes are switched on and off in cells, considered by Dr. Sinclair to be the main driver of aging through information loss (scratches).

How to Slow Aging (and even reverse it)
Veritasium
The system of chemical markers and histone proteins that package DNA, controlling which genes are turned on or off in different cell types. Loss of information here is hypothesized to be the cause of aging.

Dr David Sinclair: Can Aging Be Reversed? After 8 Weeks, Cells Appeared 75% Younger In Tests!
The Diary Of A CEO
The system that controls which genes are turned on or off without changing the underlying DNA sequence, crucial to the information theory of aging.