performing cunnilingus because there may be a high concentration of virus in menstrual blood, such as hepatitis B. HPV and oral cancer Links have been reported between oral sex and oral cancer with human papillomavirus (HPV)-infected people. A 2005 research study suggested that performing unprotected oral sex on a person infected with HPV might increase the risk of oral cancer. The study found that 36 percent of the cancer patients had HPV compared to only 1 percent of the healthy control group. A 2007 study found a correlation between oral sex and throat cancer. It is believed that this is due to the transmission of HPV, a virus that has been implicated in the majority of cervical cancers and which has been detected in throat cancer tissue in numerous studies. The study concludes that people who had one to five oral sex partners in their lifetime had approximately a doubled risk of throat cancer compared with those who never engaged in this activity, and those with more than five oral sex partners had a 250 percent increased risk. Mechanical trauma to the tongue The lingual frenulum (underside of the tongue) is vulnerable to ulceration by repeated friction during sexual activity ("cunnilingus tongue"). Ulceration of the lingual frenulum caused by cunnilingus is horizontal, the lesion corresponding to the contact of the under surface of the tongue with the edges of the lower front teeth when the tongue is in its most forward position. This type of lesion resolves in 7–10 days, but may recur with repeated performances. Chronic ulceration at this site can cause linear fibrous hyperplasia. The incisal edges of the mandibular teeth can be smoothed to minimize the chance of trauma. Cultural and religious views General views Cultural views on giving or receiving cunnilingus range from aversion to high regard. It has been considered taboo, or discouraged, in many cultures and parts of the world. In Chinese Taoism, cunnilingus is revered as a spiritually-fulfilling practice that is believed to enhance longevity. In modern Western culture, oral sex is widely practiced among adolescents and adults. Laws of some jurisdictions regard cunnilingus as penetrative sex for the purposes of sexual offenses with regard to the act, but most countries do not have laws which ban the practice, in contrast to anal sex or extramarital sex. People give various reasons for their dislike or reluctance to perform cunnilingus, or having cunnilingus performed