Non-small cell lung cancer antigen 21-1 4.86ng/ml is on the high side, which may be caused by benign diseases such as pneumonia or malignant tumors such as lung cancer. Non-small cell lung cancer antigen 21-1, also known as cytokeratin 19 fragment, CYFRA21-1, is mainly found in organs rich in epithelial tissues such as lungs, breast, intestines, bladder, uterus and so on, and there will be an elevation of CYFRA21-1 when benign or malignant diseases occur in these its organs. The normal value of CYFRA21-1 ranges from 0 to 3.3ng/ml, and 4.86ng/ml is a mild elevation, which may be caused by pneumonia, cystitis, mastitis, tuberculosis, etc., and there is also a certain risk that it may be caused by non-small-cell lung cancer, bladder cancer and breast cancer. It is recommended that the patient should consult the doctor in time, combine with other tumor indicators, imaging examinations and other comprehensive analysis, and follow the doctor’s instructions for further examination and treatment.