[1] Spanish Natl Canc Res Ctr CNIO, Tumor Suppress Grp, Madrid 28029, Spain
[2] Spanish Natl Canc Res Ctr CNIO, Telomeres & Telomerase Grp, Madrid 28029, Spain
[3] Univ Valencia, Dept Physiol, Valencia 46010, Spain
[4] Univ Complutense Madrid, Dept Anim Surg & Med, E-28040 Madrid, Spain