Non-small cell lung cancer antigen 21-1 refers to the tumor marker CYF211, which is significantly elevated if its level is 100ng/ml, suggesting the possibility of non-small cell lung cancer, hepatitis, pancreatitis and other diseases. Non-small cell lung cancer antigen CYF211 is a soluble fragment of cytokeratin 19, which is valuable for diagnosing non-small cell lung cancer. Its normal range is 0-3ng/ml, so 100ng/ml is significantly out of this range and requires vigilance for the possibility of non-small cell lung cancer. It is worth noting that clinically, CYF211 can be caused by elevated diseases such as hepatitis, pancreatitis, pneumonia, prostate hyperplasia and other diseases. Therefore, elevated CYF211 alone cannot confirm the diagnosis of non-small cell lung cancer, but should be combined with other auxiliary tests and judged by a professional doctor. If the level of CYF211 is significantly increased, it is recommended that the patient should consult a doctor in time to avoid delaying the disease.