ALDH1A1 and neoplasm: Further analysis showed that the percentage of cells co-expressing LGR5 and ALDH1, LGR5 and OCT4, and LGR5 and ZEB1 in tumor-like structures formed by LGR5+ AM epithelial cells was significantly higher than that in those formed by parental AM epithelial cells (Fig. 4e; Supplementary Fig. S7).