An analysis of approximately 1 million mutations from 14 cancer types has revealed that in some tumors, up to 68% of mutations are caused by a set of proteins that inactivate viruses and prevent ancient viral DNA present in the human genome from moving around (Roberts SA et al. Nat Genet. doi:10.1038/ng.2702 [published online July 14, 2013]).
By analyzing cancers mostly from the Cancer Genome Atlas, a research team led by investigators at the National Institutes of Health found that the proteins—called apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) cytidine deaminases—mediated mutagenesis in cancers of the bladder, cervix, breast, head and neck, and lung.
Hampton T. Proteins Involved in Immunity Linked to Numerous Cancers. JAMA. 2013;310(9):894. doi:10.1001/jama.2013.277037