Gastrin-releasing precursor refers to gastrin-releasing peptide precursor, the normal value is 2~50 pg/mL, can be due to the different examination methods the results of the error, it is recommended to consult the local doctor. Gastrin-releasing peptide precursor is the precursor structure of gastrin-releasing peptide, which mainly exists in the gastrointestinal tract, respiratory tract and central nervous system, and it is a specific tumor marker for small cell lung cancer. If gastrin-releasing peptide precursor is >150 pg/mL, it is highly suggestive of small cell lung cancer, and it is more accurate if combined with neuron-specific enolase to diagnose small cell lung cancer. Elevated gastrin-releasing peptide precursor is also commonly seen in certain neuroendocrine tumors, such as medullary thyroid carcinoma, etc., and in certain benign diseases, such as urinary and respiratory diseases. In addition, renal failure may also present with elevated gastrin-releasing peptide precursor. Gastrin-releasing peptide precursor can also be used for efficacy monitoring, recurrence detection and assessment of prognosis, which often decreases after treatment, and if it continues to be elevated, recurrence or poor prognosis of small cell lung cancer is considered. When abnormalities of gastrin-releasing peptide precursor occur, it is recommended to consult a physician for prompt diagnosis and treatment.