To better understand the role of TFF1 during H. pylori infection, we analyzed two cancer cell lines with significant difference in TFF1 basal levels: AGS, a gastric adenocarcinoma cell line, highly differentiated, intestinal type, which shows very low expression of TFF1, almost undetectable at protein level; KATO III, a signet ring cell carcinoma from a metastatic site, poorly differentiated, with higher expression of the protein (Supplementary Figure 1). Here, TFF1 is linked to signet ring cell carcinoma.