From the article by Breanna Draxler in DISCOVER . It's not quite what we're talking about in A REMEDY FOR DEATH, but it's a step in that direction.
"Move over, anti-aging cream. Researchers have found a new biological clock in human DNA that determines the rate at which bodily tissues age—revealing some surprising things about which parts of our bodies feel the brunt of aging soonest, and how such aging may eventually be reversed."
"Researchers found, for example, that healthy breast tissue is usually two or three years older than the rest of the tissues in a woman’s body. This could be due to the concentration of hormones in breast tissue and could potentially explain why the breast is the most common site of cancer for women.
"Heart tissue, on the other hand, tended to be about nine years younger than the rest of a person’s tissue samples, most likely because it is constantly being regenerated by stem cells. On the extreme ends of the spectrum, researchers found that cancer cells are on average 36 years older than the rest of the body, whereas pluripotent stem cells are a constant age 0."
Just thought you'd want to know. And bear it in mind some grey Monday morning when the working week looms ahead and your heart is telling you "I'm too old for this." Respond, "Well, heart, not really!"