Aging: Several studies indicated that de novo appearance of NUMT pseudogenes in the genome of somatic cells may be of etiological importance for carcinogenesis and aging. To show the relation between aging and NUMT in the nuclear genome, Cheng and Ivessa used "yme1-1" mutant strains of Saccharomyces Cerevisiae that have a higher rate of mtDNA migration. The method is exactly the same as the method Thorsness and Fox used to determine the important mechanisms and factors for mtDNA migration into the nucleus. They found out the yeast strains with elevated migration rates of mtDNA fragments to the nucleus showed accelerated chronological aging, whereas, strains with decreased mtDNA transfer rates to the nucleus exhibited an extended CLS, chronological life span which could possibly be due to the effect of NUMT on nuclear processes including DNA replication, recombination, and repair as well as gene transcription. The effect of NUMT on the higher Eukaryotic organisms was investigated by Caro and his teammates in the rats as a model organism. Using a real-time PCR quantification, in situ hybridization of mtDNA to nDNA, and comparison of young and old rats, Caro and his crew not only could determine the high concentration of cytochrome oxidase III and 16S rRNA from mtDNA in both young and old rats, but they also could find out the increase in the number of mitochondrial sequences in nDNA as the rat gets older. Thus, based on these findings, mitochondria can be a major trigger of aging, but the final target could also be the nucleus.