THY1 and gastric cancer: In the context of these theories of gastric cancer carcinogenesis, the clustering pattern of different stem/progenitor cell markers seen in the TCGA data is interesting (Fig. 2a), which suggest that there may be at least two different signatures of stem/progenitor gene expression, i.e. one more intestinal (cluster #1, LGR5-high) and one more MSC-like (cluster #2, THY1-high).