150 patients were recruited, who have diagnosed with acute leukemia by bone marrow biopsy

The 50 healthy controls without previous cancer history were recruited from individuals who visited investigator's hospital for physical examination during the same time period as the case enrollment.

Mitochondria are responsible for multiple cellular functions including regulation of energy production, modulation of oxidation-reduction status, generation of reactive oxygen species and apoptosis. Each mitochondrion possesses multiple copies of a mitochondrial genome comprised of independently replicating double stranded DNA (mtDNA).

The ratio of mitochondrial DNA contents to hemoglobin contents was calculated for each sample from standard curves. After that, the ratio for each sample was normalized to a calibrator DNA in order to standardize between different runs, and then defined as the measurement of relative mtDNA contents.Relative expression of mtDNA were measured in young adults suffered from chronic lymphocytic leukemiawhen compared with control group.