Transition of the major subpopulations of mtDNA mutants in CD34⁺ cells from each healthy donor in 2 years. Our present data about the proportion of major subpopulations of mutant mtDNA in single CD34⁺ cells from 5 healthy donors were compared with our previous publication data. We used the sequence data of mtDNA control region in CD34⁺ clones derived from the same donors' bone marrow 2 years before this study (2002)¹⁸  and derived from peripheral blood 1 year before this study (2003).¹⁹