The progression from cin1 to cin3 takes about 1-2 years clinically, but this time is not absolute as individuals vary. Some people can transform from cin1 to normal, and some people transform from cin to cin3 in less than 1 year. Therefore, if a patient with cin1 has undergone localized cervical treatment, it is recommended that he or she be retested at 3 months, half a year, and 1 year, respectively, to find out if the cervical epithelium is still diseased or if he or she still has high-risk HPV. If he or she has a high-risk HPV infection, he or she must undergo colposcopy, and according to the results, he or she should be given an intervention to prevent the progression of the lesion to a more advanced level.