Mitochondrial respiratory chain (MRC) consists of the protein complexes I, II, III, IV, and V to carry oxidative phosphorylation (OXPHOS), which depends on electron transport to generate ATP. Electron "leakage" from MRC generates reactive oxygen species (ROS). Chronic myeloid leukemia in chronic phase (CML-CP) stem cells (LSCs) produce high levels of mitochondrial ROS causing oxidative DNA damage resulting in genomic instability generating imatinibresistant BCR-ABL1 kinase mutants and additional chromosomal aberrations. Using global mRNA microarray analysis combined with Ingenuity pathway analysis we found that LSCs display enhanced expression of genes encoding MRC complexes I, II, IV, and V. However, expression of genes encoding complex III was deregulated. Treatment with imatinib did not correct the aberrant levels of MRC genes. Therefore we postulate that abnormal expression of MRC genes may facilitate electron "leakage" to promote production of ROS and accumulation of genomic instability in LSCs in imatinib-naive and imatinib-treated patients.