High pepsinogen 1 suggests increased secretion of gastric mucosa, which is usually not a manifestation of gastric cancer, and is mostly seen in peptic ulcer, gastritis and other diseases. Pepsinogen 1 belongs to one of the subtypes of pepsinogen, which is mainly secreted by gastric fundus master cells and cervical mucus cells, and its change level can reflect the change of gastric mucous membrane to a certain extent. When pepsinogen 1 is elevated, it suggests an increase in gastric acid secretion, which is often seen in peptic ulcer, gastritis and other diseases with increased gastric acid. When pepsinogen 1 decreases, it suggests that the secretion of gastric acid decreases, and the secretion function of gastric mucosa decreases, mostly seen in atrophic gastritis, gastric cancer, and other diseases that increase the destruction of gastric glands. Therefore, high pepsinogen 1 is usually not a manifestation of gastric cancer, and further gastroscopy and biopsy are needed to diagnose gastric cancer.