Awakening of Ancient Retrovirus:A New Sign of Aging in Humans?

Endogenous retroviruses（ERVs） are viral elements that have been incorporated into the host genomes of mammals over time and have evolved to become part of the host genome.Some ERVs have been domesticated and serve a role in host development and health.HML-2,a recently integrated family of human endogenous retrovirus K（HERVK）（GarciaMontojo et al.,2018）,is an example of such ERVs and is transcribed during early human development to encode viral proteins that are proposed to promote antiviral immune response and specialization of primordial germ cells（Grow et al.,2015; Xiang et al.,2022）.