The modern classification of CIN2-3 includes moderate to severe atypical hyperplasia as well as carcinoma in situ. CIN refers to cervical intraepithelial neoplasia, which is a precancerous lesion of the cervix; CIN2 is equivalent to moderate atypical hyperplasia, which refers to atypical hyperplasia accumulating in the lower 1/3 to 2/3 of the epithelial layer; and CIN3 refers to lesions extending beyond the 2/3 of the epithelial layer, accumulating in the whole layer of the epithelium, which is carcinoma in situ. CIN2-3 suggests that the patient has a high risk of precancerous lesions, which usually requires LEEP knife surgery, or total hysterectomy if there is no need for childbearing, after which further treatment and review are required.