In GCSCs, EpCAM and CD54 were highly expressed on the cytomembrane, CD133 was weakly but Lgr5 and Oct4 were highly expressed in cytoplasm, and Sox2 was highly expressed in cytoplasm and nucleus (Figure 1). The expressions of these markers in primary lesions and metastatic LNs of GC through IHC were similar to GCSCs, except that CD133 was mainly expressed in the lumen of glands and Oct4 was expressed in nucleus (Figure 2). The relationships among these six markers in primary lesions were also analyzed and showed that EpCAM had significantly negative correlation to Lgr5 (p=0.007), CD133 (p=0.006) and Oct4 (p=0.001), while Oct4 was positively associated with Lgr5 (p<0.001) and CD133 (p=0.024) in immunohistochemistry (IHC). With respect to quantitative polymerase chain reaction (qPCR), we found that Lgr5 and Sox2 were remarkably positively correlated with CD54 (p=0.006) and Oct4 (p=0.006), respectively (Table 1).