LGR5 and neoplasm: At day 14 post transplantation, histological analysis showed that parental and LGR5+ AM epithelial cells could proliferate and generate tumor-like structures, but transplanted LGR5− cells could not survive and were almost completely resorbed (Fig. 4b), wherein the presence of human AM epithelial cells in vivo was confirmed by immunostaining with a specific antibody for human mitochondria (Fig. 4c).