ck20 is Cytokeratin 20, ck20 is an immunohistochemical test indicator for keratin, which is generally found in epithelial tissue and is an important marker for cancer or tumors. Almost all intestinal adenocarcinoma, part of gastric cancer is (+), uroepithelial cell carcinoma can be (+), ck20+ indicates keratin is positive, indicating that it may be suffering from malignant neoplastic diseases originated from epithelial tissues, which need to be combined with other immunohistochemistry test results to make a comprehensive judgment, in which the common diseases are gastrointestinal adenocarcinoma, ovarian mucinous tumors and so on. Generally speaking, ck20+ indicates that keratin is positive, which means that the patient’s epithelial tissue may have malignant tumors, which may be related to gastrointestinal adenocarcinoma, ovarian mucinous tumors, Merkel cell carcinoma and other diseases. However, this is not absolute, patients also need to combine with other examinations to make a comprehensive judgment, such as ultrasound, CT, MRI, etc., so as to have an understanding of the tumor’s location, pathological type and staging results, and actively cooperate with the doctor’s treatment.