The chemokines CCL2, CCL4, CCL5, CCL22 and CXCL8 are known to play a role in the migration of Tregs into inflamed or tumour tissues.14–16 Others, including CCL2-5, CCL20 CCL22, CXCL1-3, CXCL8 and CXCL10 are upregulated in the H pylori-infected gastric mucosa,5, 17–20 and expression of chemokine receptors and other adhesion molecules by immune cells is also increased.10, 21, 22 Our first step was to narrow down this array of homing molecules and receptors to those that might be important in Treg migration to the H pylori-infected gastric mucosa. Here, CCL22 is linked to neoplasm.