ABCG2 and gastric cancer: We chose a set of genes that were reported to encode gastric cancer stem cell markers such as LGR5, CD133, CD44, CD54, ABCG2 and MSI1, and then performed qPCR to detect their expression in both NANOGP8-transfected (SGC7901-NANOGP8) and mock cells (SGC7901-NC).