Introduction. Aging in mitotic and post-mitotic cells (J. Campisi, H.R. Warner). Age-associated changes in DNA repair and mutation rates (L. Gro ssman, S.-I. Moriwaki, S. Ray, R.E. Tarone, Qingyi Wei, K.H. Kraemer). R elationship of DNA repair capacity to species lifespan (R.W. Hart, A. Tu rturro, S.Y. Li). DNA base modifications in aging (J.W. Gaubatz). Models for studying genomic instability during aging (J. Vijg, H. Giese, M.E.T . Dolle). Effects of aging on gene specific repair (A. Richardson , ZhongMao Guo). Poly (ADP-RIBOSE) Polymerase and aging (D.S. Rosenthal, C.M. Simbulan-Rosenthal, Wen Fang Liu, M.E. Smulson). DNA instability, telomere dynamics, and cell transformation (R.J. Shmookler Reis, M.A. Sh ammas). Commitment signalling for apoptosis, or DNA repair and its relev ance to aging and age-dependent diseases (E. Wang, R. Marcotte, H.T. Pap aconstantinou, J. Papaconstantinou). DNA damage and its processing with aging: human premature aging syndromes as model systems (V.A. Bohr). Gen e action at the Werner helicase locus: its role in the pathobiology of a ging (J. Oshima, G.M. Martin, M.D. Gray, M. Poot, P.S. Rabinovitch). Ind