[dahfizz]

This sounds a bit like a technicality. The DNA makes it into the cell nucleus and is used by the cell machinery to make proteins. The changes aren't carried over after cell division, but lots of cells in your body last your whole life (nerves, brain cells, eye cells, important stuff).

[ipaddr]

I was under the impression all cells in the body will be regenerated in 7 years.

[laplacesdemon48]

Loss of neurons and cardiac muscle cells is permanent. Emergency medical personnel are usually taught "time is brain" and "time is heart" for this reason.

Some body cells can bounce back after serious trauma, liver cells being a prime example: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2701258/