In contrast to other tumour cells, CSCs are drug-resistant, and show the ability to self-renew and differentiate.41,42 It has been shown that CD117 was up-regulated in lung CSCs and ovarian CSCs, and mediated chemoresistance.39,43 It is likely that CD117 up-regulates the stemness of tumour cells and is involved in chemoresistance in oesophageal SCC as well, which may provide an explanation for our observation that the nearly 30% of oesophageal SCC patients whose tumours expressed CD117 had shorter survival times than those with CD117-negative tumours. The gene discussed is KIT; the disease is neoplasm.