Senescent cells is a state of permanent cell cycle arrest where cells that have ceased cell division and growth in the cell cycle. They are often referred to as zombie cells as whilst they don’t replicate, they are still very metabolically active and continue to accumulate as we age. These senescent cells continue to secrete inflammatory molecules called cytokines and hence they are like active zombies. The secretion of these pro-inflammatory chemicals causes CD38 expression (a multi-faceted ecto-enzyme that metabolizes NAD+) causing our NAD+ levels to drop. These senescent cells further excrete protein signals to inflame surrounding tissues to turn into senescent cells and drive tumors to grow and spread.

Both human and animal studies how shown that if you get rid of them, the body recovers and heals and becomes more youthful and you could be partially rejuvenated.