Gastritis is known to cause elevated cytokeratin 19 fragment. Cytokeratin 19 fragment is a new tumor marker of epithelial origin, which is important for early diagnosis of non-small cell lung cancer. In addition, for patients with breast cancer and cervical cancer, their serum cytokeratin 19 fragment will also be high. However, high cytokeratin 19 fragment is not necessarily a malignant tumor, but may also be a common inflammatory disease, such as gastritis and bronchitis. Patients with the above symptoms may also have slightly elevated serum cytokeratin 19 fragments, but the elevated values will not be more than a few times the normal value, and generally will not be persistently elevated. In conclusion, if the serum cytokeratin 19 fragment is found to be high, it is recommended to improve the systematic examination under the guidance of a doctor to exclude the possibility of cancer.