How would you define the regenerative potential of a tissue/organ?

Dear stem cell biologists and bioinformaticians: I’ve got a pretty serious question for you. How would you define and quantify the native (endogeneous, in-built) regenerative potential of a tissue/organ or more generally of a specially localized functional cell population in the human body? In the literature the term “regenerative potential” of a tissue is often

Best paper on stem cells and ageing by Thomas Rando: Figure 1

One of the promo material of last December Cambridge Embryonic Stem Cell Symposium was the Nature Insight: Stem Cells which was a supplement in Nature Vol. 441, No. 7097 pp1059-1102 from June , 2006. In it I found the best, brilliantly argumented and conceptualized, data-rich paper of Thomas Rando from Stanford University on Stem cells,