In cancer patients, “mesenchymal CTCs” (epithelial marker CK/E-cadherin negative, mesenchymal marker vimentin/N-cadherin positive) are chemoresistant [20, 33, 34], which keeps in agreement with our previous report indicating the majority of gastric cancer CTCs were CK18- and chemoresistant [16]. This evidence concerns the gene CDH2 and gastric cancer.