The seven most important elements of the XGBoost model were CRP level, smoking, liver disease, minimum systolic blood pressure, gastroscopy as the first endoscopy, intervention at first endoscopy, and previous GIB; in the CatBoost model, the most influential conditions were CRP level, smoking, melaena, minimum systolic blood pressure, previous GIB, Glasgow Coma Scale (GCS) and haemoglobin level. The gene discussed is CRP; the disease is liver disorder.