ALDH1^high cells have a high tumor-initiating ability.

<p>A, Representative image of a tumor-bearing NOD-SCID mouse. (right: ALDH1^<b>high</b> cells, left: ALDH1^<b>low</b> cells). B-D, Immunohistochemical (IHC) staining of the xenograft tumor sections. The sections were stained for hematoxylin, myogenic markers (Desmin (B), Myogenin (C)) and ALDH1 (D). The tumor cells were positive for Desmin and Myogenin while only a few cells were positive for ALDH1, suggesting that the ALDH1^<b>high</b> cells promoted rhabdomyosarcoma and were reconstituted to incorporate the full range of heterogeneity.