So do cells in embryos, but the telomerase gene is inactivated in most cells after birth. Reactivating telomerase could replenish lost cells. Warner mentions the possibility of restoring epithelial cells in the retinas to restore lost eyesight. Telomerase genes have been successfully reactivated in retinal epithelial cells grown in tissue culture, in work done at the University of Texas Southwestern Medical Center and the Geron Corporation . Geron has filed for patents on hTRT, the telomerase reverse transcriptase protein.
Cancer cells are all about telomerase and unrestricted cell division.
Steven Austad is a zoologist who studies aging. Austad notes that when we discover and examine genes in the human genome that can increase longevity, they may prove to come with trade-offs. And they all have downsides. People have not been eager to investigate the nature of their downsides. Cancer obviously could be a downside, as could altered fertility.