All known papillomavirus types infect a particular body surface,[2] typically the skin or mucosal epithelium of the genitals, anus, mouth, or airways.[8] For example, human papillomavirus (HPV) type 1 tends to infect the soles of the feet, and HPV type 2 the palms of the hands, where they may cause warts. Additionally, there are descriptions of the presence of papillomavirus DNA in the blood and in the peripheral blood mononuclear cells.