Intraepithelial neoplasia, also known as intraepithelial neoplasia (IN), is a diagnostic term commonly used in clinical pathology diagnosis and covers atypical proliferation or dysplasia of epithelial tissues in multiple organs. The organs involved include the cervix, prostate, endometrium, esophagus, gastrointestinal and other organs of the digestive system. IN is a special stage before the occurrence of epithelial malignant tumors. IN has obvious changes in cell morphology and cell arrangement compared with normal tissues. There are also clonal changes in genetics and a certain degree of invasiveness in biological behavior. .