| Comments |
P.1484 left column bottom paragraph: "In the absence of selection or clonal proliferation, one can estimate the number of spontaneous mutations that could accumulate in stem cells with the potential to proliferate into a tumor. Based on studies in human bone marrow, it has been estimated that only 0.002% of the cells can form colonies with high proliferative potential (BNID 112677) and thus can operationally be considered as stem cells. Assuming that a similar fraction of cells in other tissues is stem cells, and that the average stem cell undergoes 100 divisions during a human lifespan, then the cellular target size for mutagenesis is approximately (2×10^14 cells per adult) (0.002%) or 4×10^9 cells." |