Human papillomavirus (HPV) is the most common sexually transmitted infection. There are many different types of HPV, and while the majority are usually harmless and go away on their own, some variants of this virus are capable of causing genital warts or even specific types of cancer. 

This is what is referred to as High-Risk HPV.

There are more than 100 different variants of HPV and at least 14 of these are cancer-causing and labeled as high-risk. High-risk HPV can cause normal cells to become abnormal, and these abnormalities can potentially lead to cancer over time if left undiagnosed and untreated. High-risk HPV most often will affect cells in the cervix, but it may also cause cancer to appear in the vagina, vulva, anus, penis, mouth and throat.  

Among this group of high-risk HPV variants there are two particular strains (types 16 and 18) which cause 70% of cervical cancers and pre-cancerous lesions.