How can viruses cause cancer?
Some virus infections can cause cancer, though the disease often appears several decades afterwards. For example, cancer of the cervix is linked to infection with the human papilloma virus (HPV) that causes genital warts. In this case, the DNA in the virus mixes with the cell's DNA, triggering changes that make the cell grow and multiply. From 2009, girls in the UK have had access to a vaccine that prevents infection with HPV and thus protect them from developing cervial cancer as a result.