Negative expression of MUC1 was found in cases of the common, drug-induced, and Hp infection-induced hyperplasia of gastric epithelial cells, while positive expression (+) of MUC1 was identified in cases of metaplastic hyperplasia of gastric epithelial cells, atrophic hyperplasia of gastric epithelial cells, low-grade neoplasia of epithelial cells, and high-grade neoplasia of epithelial cells. This evidence concerns the gene MUC1 and neoplasm.