It is not possible to determine the severity of the disease based on Keratin 19 Fragment 5.47 alone. Cytokeratin 19 is distributed on normal tissue surfaces, such as in stratified or squamous epithelium, and is normally <3.30 ng/ml. Cytokeratin 19 is mildly elevated in isolated benign liver disease and renal failure. A lesion in the lungs that cannot be definitively diagnosed that is accompanied by increased cytokeratin 19 (>30ng/ml) predicts a fairly high likelihood of primary bronchopulmonary cancer. Cytokeratin 19 is the tumor marker of choice for the detection of non-small cell lung cancer and is used primarily for disease surveillance in patients with non-small cell lung cancer, but also for monitoring the course of rhabdomyolysis-invasive bladder cancer. High levels of cytokeratin 19 often indicate advanced tumor stage and poor prognosis. Keratin 19 fragment 5.47ng/ml should be timely to the hospital to clarify the cause of the disease, early diagnosis and early treatment.