Capacity of ALDH+and ALDH+/GD2+cells to undergo differentiation in vivo . Mammospheres derived from BC-P007 Aldehyde dehydrogenase 1 (ALDH)+ cells were engrafted. Five thousand ALDH+ cells were injection into fat pads and on Day 86, severe tumor nodules were observed in the thoracic cavity. In addition to tumor at the injection site, one of the metastatic tumors removed for H&E staining revealed the presence of cells with lacunar space, suggestive of chondroid cells (A. 200×), which was confirmed by Alcian blue staining (B. 200× ) and anti-collagen type II staining (C. 200×). In addition, the metastatic tumor was examined by staining for neuro-ectodermal cell lineages markers, including nestin, ßIII-tublin and GFAP (D. 400X). Fifty ALDH+/GD2+ cells sorted from the BC-P007 xenografted tumor were engrafted and the tumor was removed on Day 61(E). H&E staining revealed the presence of neuron-like cells (circles) (F. 200×). The tumor was examined for the expression of collagen type II, nestin, βIII-tublin and GFAP by immunohistochemical staining. The right upper region expressed anti-human collagen type II (G. 200×), and the left upper region expressed nestin moderate staining, βIII-tublin and GFAP expressed weak staining (H. 400×).