History of Research in Aging Networks Tarynn Witten, Virginia Commonwealth University 4 December 2009 While an interesting paper, this paper ignores the significant previous literature in the field of aging networks, reliability theoretic applications to aging networks and purports to be the first to generate the ideas of using hubs and other network concepts to understand the behavior of aging processes. Unfortunately, the ignored literature significantly overlaps the results in this paper. The work of Witten, as far back as the early 1980's represents the actual first publication of the concepts of central elements and centrality of networks using graph theoretic concepts in aging. Witten, T.M., A return to time, cells, systems, and aging: II. Relational and reliability theoretic aspects of senescence in mammalian systems, Mech. Aging and Dev., 27 (1984) 323--340. This work documented the idea of what is now called essential genes (Witten called them critical elements) and highly connected hubs. This work was followed by a number of publications applying network and reliability theory to aging networks: Witten, T.M., Reliability theoretic methods and aging: Critical elements, hierarchies, and longevity---Interpreting survival curves, (in) The Molecular Biology of Aging (eds.) A. Woodhead, A. Blackett, and R. Setlow (Plenum Press, N.Y. 1985). Witten, T.M., A return to time, cells, systems and aging: III. Critical elements, hierarchies, and Gompertzian dynamics, Mech. Ageing and Dev., 32 (1985) 141--177. More recently, these methods were extended using the Bonchev-Witten algorithm to determine potential longevity-related genes in longevity-gene networks. Witten, T.M. and Bonchev, D.G. (2007). Predicting aging/longevity-related genes in the nematode C. elegans. Chemistry and Biodiversity, 4: 2639-2655. The following paper provides a history of the work: Witten, T.M. (2007). (M,R)-systems, (P,M,C)-nets, hierarchical decay and biological aging: Reminiscences of Robert Rosen. Chemistry and Biodiversity, 4 (10): 2332-2344. Most recently, Witten's doctoral student Managbanag along with the research team at U of Seattle, using the methods developed by Bonchev and Witten published the following paper: Managbanag, J.R., Witten, T.M., Bonchev, D.G., Fox, L.A., Tsuchiya, M., Kennedy, B.K. & Kaeberlein, M. (2008). Shortest-path network analysis is a useful approach towards identifying genetic determinants of longevity. PLoS ONE, 3 (11):e3802. doi:10.1371/journal.pone.0003802 It is extremely disturbing to discover that all of these works were ignored in the reference list of the Simko et al (2009) paper [also ignored in other papers published in other locations] and that the current paper Simko et al (2009)purports to present the idea that they are the originators of ideas whose core was published by Witten over 20 years ago. We hope that this lack of attention to the core literature in the field of networks in aging will be rectified in the future by these and other authors. Competing interests No competing interests.