TFAM and neoplasm: 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.