It appeared that the extents of activation by IGF2 and insulin were different.Expression levels of genes involved in mitochondrial biogenesis like PGC1α, PRC1, PNC1,NRF-2a, NRF1, TFAM, and MFN1 and genes involved in mitochondrial activity like NFE2L2, COX1,and cytoB were higher in breast cancer cells treated by IGF2 than that in cells treated byinsulin. The gene discussed is MFN1; the disease is breast carcinoma.