Moreover, this increase is particularly marked in stages I and II, indicating that mtDNA copy number plays an important role during the initiation of CRC.25 Wen et al. have demonstrated that increased mtDNA copy number mediated by p53-upregulated TFAM is significantly related to advanced Tumor, Node, Metastasis stages, positive lymph nodes, and low 5-year survival rate in patients with CRC.26 Therefore, it seems likely that increased mtDNA copy number would promote the progression of CRC. This evidence concerns the gene TP53 and colorectal carcinoma.