Non-small cell lung cancer antigen generally refers to the non-small cell lung cancer associated antigen, cytokeratin 19 fragment, 5.12ng/ml has a mild elevation, which may be caused by benign diseases such as pneumonia or malignant tumors such as lung or breast cancer. Cytokeratin 19 fragment (CYFRA21-1), the preferred tumor marker for non-small cell lung cancer, has a normal value of less than 3.3 ng/ml.Elevated CYFRA21-1 can be seen in lung cancer as well as malignant tumors, such as breast cancer, colorectal cancer, and bladder cancer, and benign diseases, such as mastitis, pneumonia, and tuberculosis. A CYFRA21-1 value of 5.12ng/ml is considered mildly elevated (<10ng/ml is considered mildly elevated), which is mostly seen in benign diseases, but the possibility of malignant tumors cannot be ruled out. It is recommended that the patient should consult the doctor in time, combine with other tumor indicators and imaging examinations to make a comprehensive judgment, and follow the doctor's instructions for further examination and treatment.