There are 138 known subtypes of HPV, 40 of which cause epithelial infections of the genital tract. There are two types of HPV according to their carcinogenicity: 1. Low-risk HPV (non-cancer-related, LRHPV): including HPV6, 11, 42, 43, etc. It is generally believed that this type of HPV infection does not induce cervical cancer. 2. High-risk HPV (cancer-associated, HRHPV): including HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59; HPV66, 70, 53, 67, 83, AE5 may also be cancer-associated. Among them, HPV16 and HPV18 are the most common. are generally considered to be closely related to the development of cervical cancer.