Human papilloma virus: DNA analysis of anogenital warts,CIN and cervical cancerous tissue has shown that two groups of HPV can be identified in the female genital tract. One group of HPV (type 6,11)is almost always associated with low grade CIN lesions and exophytic anogenital warts which have a
low risk of progressing to cervical cancer. A second group (HPV type 16, 18) is found most commonly in CIN2 and CIN3 which have a
high risk of developing into invasive cancer.