1 Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, 617 Hunterian Building, 725 N. Wolfe Street, Baltimore, Maryland 21205, USA. cgreider@bs.jhmi.edu
Telomere length has been proposed to signal entry into cellular senescence. Expression of the human telomerase subunit, hTERT, in primary cells now shows that these cells bypass senescence.