https://phys.org/news/2018-07-ribosome-genes-aging.html

"Ribosomal DNA is one of the major hotspots for instability in the genome," said Silvana Paredes, the research scientist who led the study.

Working in Katrin Chua's laboratory, which is jointly affiliated with Stanford and the Geriatric Research Education and Clinical Center at the VAPAHCS, Paredes examined the relationship between aging, rDNA, and a protein called SIRT7. SIRT7 helps modify the proteins that DNA winds around, which affects whether genes are turned on or off. Paredes found that SIRT7 was important for keeping parts of the rDNA turned off.