CD44 and gastric cancer: In addition to having the capacity for self-renewal and differentiation.4 CSCs are more resistant to chemotherapy than non-CSCs and may be the source of metastases.5 Gastric CSCs have been identified and distinguished by several cell-surface markers including CD133, CD24 and CD44.6–8 Takaishi et al. test in six gastric cancer cell lines for seven CSC markers and their association with CSC properties, and found that CD44 was the only gastric CSC marker associated with tumour formation in immunodeficient mice and spheroid colony formation in vitro.9