To further verify the cellular origin of LCN2, we performed mIHC, and the results showed that there were a large number of cells co-staining with MUC6 and LCN2, and some cells co-staining with MUC5AC and LCN2 in both the gastric corpus with pyloric gland metaplasia samples and non-atrophic gastritis, indicating that LCN2 is expressed primarily in epithelial cells, and the increased LCN2 during pyloric gland metaplasia mainly originates from epithelial cells (Figure 5G). Here, MUC5AC is linked to chronic atrophic gastritis.