Human papillomavirus (HPV) describes a group of viruses that affect the skin and moist areas of the body such as the cervix, mouth, back passage and throat.
It spreads through skin-to-skin contact, including sex, and most people are infected with it at some point in their lives without it causing them any harm.
But in some people the virus can linger and cause cells to divide more rapidly than usual, and eventually develop into cancer.
HPV causes around 5% of all cancers worldwide and one case every hour and 15 minutes in the UK.
It appears most commonly as cervical cancer but can also cause cancer of the vagina, vulva, penis, anus and mouth.
HPV is to blame for almost all of the 3100 new cases of cervical cancer annually, which kills 850 women a year.
The virus, which can be passed on during oral sex and kissing, is also behind a sharp rise in throat cancer in young people.
Once most common in elderly drinkers and smokers, throat tumours are now as likely to be found in people in their 50s as those in their 80s. Daily Mail